If the answer is "the police", I'm not really sure what having the blockchain gets us, if anything at all. Recording changes at the county recorder is easy and cheap enough already, so what's the point?
In the case of calling the police, it establishes that there exists a trusted authority, breaking condition (2).
Since there doesn't seem to be a way to decentralize the enforcement of real property ownership (as enforcement could involve violence, which the state has a monopoly on given our current social contracts), we're stuck with centralization in at least one component of the "ownership-enforcement" pair...
So then what's the point of decentralization at all?
Private security firms exist. One theory for a way forward (not advocating): https://mises.org/library/private-production-defense
Anarchy, State, and Utopia by Nozick addresses some of the holes in this text, but there are options.
At best, the blockchain is superfluous, at worst misleading, since whilst the tangible benefits of ownership rests with what the county recorder says, you can sell notional claims to ownership of the property on blockchains to other people, potentially multiple other people all thinking their token on their blockchain is canonical. The priority of the enforcing agency is a much bigger issue for real world property rights than the mutation of records
This seems like the opposite of true to me; if they intend to mutate the records doesn't it become extremely helpful that the records are immutable? What am I missing?
That said, the same thing can be accomplished by outsourcing the public ledger to a third party with a reputation for trustworthiness. The same way that countries that cannot make a credible commitment to not devalue their money will often peg their currency to the dollar or the euro.
Which is where trusted counterparties like the one you suggested are a much better bet than an untrustworthy party enforcing and administering a record and its exception handling, even if that record itself is immutable.
Somebody puts an entry on the blockchain that says they own my house. OK so what? Nobody cares. They can't get that enforced. If you want to make the sale "real" to the authorities, you have to enter it into the land registry - but now you have a coordination problem. Do we put it into the blockchain first (and hence you pay first) and then the land registry? Or vice versa? Either one requires trust. Hm, maybe we better involve a trusted third party like an escrow company... oh wait we just reinvented the existing system.
All of this is not dissimilar to people selling NFTs of someone else's art. And you'll see the same problems if/when they try to violate copyright on that basis.
If you could convince the relevant authorities that the blockchain was the system-of-record then you'd have something useful. But with all the problems of losing ownership, hacking, inability to recover defrauded assets, etc, what are the odds of that happening?
https://www.alchemy.com/ (currently valued at $3.5B)
https://infura.io/ (actually Consensys and valued at $3.2B)
For IPFS there's the Infura product and Pinata (which actually uses AWS).
While these may not be "crazy" valuations for the space it seems that many people and investors are aware that the utopian concept of everyone running their own node or whatever for access to/participation in these blockchains is more-or-less a pipe dream. You can check my comment history for examples of why these node providers are a necessity for anything other than toy blockchain use cases.
What's interesting about these providers is that (once again) you're trusting a single source. The blockchain isn't the blockchain - the blockchain is whatever your commercial and centralized node provider says it is. I have no reason not to trust them but the reality is not only are we back to centralized providers, we're back to inherently trusting them.
The gist of it is: if web3 is real and actually "takes over" companies like Alchemy and Infura are just the new AWS and GCP:
https://www.alchemy.com/company
Consensys is even more telling:
https://consensys.net/products/
Large node provider, wallet (MetaMask!), and popular development suite (Truffle) - among others.
First, your apps API to one of those node providers is standardized and stateless. Switching to a different one could not be more simple: changing a url in your config file; there is basically no lock-in.
Second, running your own is by no means impossible. If you don't need an archive node, it is almost straightforward. It's certainly much easier than replacing all of your AWS dependencies.
Third, for simple apps, the interaction with the node can be entirely browser-side, so it can be users choice which provider is used. For complex stuff you need to write an indexer to create the state you need, which is actually a more interesting problem because it does often mean that the smart contracts themselves cannot be served by a static HTML page, ergo making your product a centralizing factor. This is essentially what the The Graph is trying to solve.
Fourth, there is another layer below all of this product-node interaction, that is more important - the nodes running the consensus. The nodes we are talking about here are just to access a copy of the state. There is value in consensus being spread over 20k nodes, even if all the web apps use Alchemy.
Fifth, "trust" is nuanced. You have to ask yourself what failure cases you want to address. What power does Alchemy have over the network or the ecosystem? The answer is not much.
That said there needs to be some perspective in between the "eat the world this is the greatest thing ever hype-beast pump pump pump echo chamber bubble" and "this is completely stupid, worthless, and will never be anything" camps in all things blockchain. Anyway...
With all due respect "...running your own is by no means impossible. If you don't need an archive node, it is almost straightforward." is classic HN. The fact that Alchemy and Infura alone have hundreds of thousands of customers up to and including arguably THE most prominent names in the blockchain space demonstrates just how far from reality and common use that statement is.
Alchemy isn't a $3.5B company because someone threw HTTPS load balancers in front of a few Ethereum nodes... First, having used Alchemy and Infura I've noticed clear differences in how they handle sync, state, etc. Alchemy prides itself on sync and state between individual nodes in their network - using the web3 API and calling latest (or pending) nonce appears to be extremely reliable when compared to others (as an example).
Infura, on the other hand, seems to be relying on their ITX ("Transactions") product to deal with the very real and extremely frustrating web3 API issues for actually getting transactions to happen reliably, with predictable gas fees, etc.
My application and use is currently very simple and I've encountered these issues - I'm certain there are larger practical differences between the node providers. Again Alchemy isn't a $3.5B company because they have no differentiators and no customer lock-in.
So far we have basic implementation quirks and higher level products to "just make transactions actually work" and "just make an NFT". You can count on there being many more on the way and you know what? Companies will be THRILLED to use them.
Is the average user (or even developer/company) going to run their own node? Definitely not. Is the average user of Metamask tweaking the node addresses? Does the average user know what any of this gibberish means? Definitely not. Metamask users are going to use whatever default node address it has. There are 13,000 Bitcoin nodes and roughly (at best) 10,000 Ethereum nodes. Coinbase (as one example) has 56 million users. Once again people are not making the decision to fire up their own node or in most cases even have their own wallet. For all the same reasons people aren't hosting their own e-mail server from a raspberry pi at their house. They get a Gmail address and move on with their lives.
When I've configured Metamask for Polygon (as an example) it isn't extremely clear and obvious which RPC node addresses are actually "official" or "authoritative" for a given network... I've been developing with Ethereum and Solidity for four years. I've run my own nodes. I've built applications to multiple providers, networks, etc. I had 200 Nvidia Pascal GPUs mining Ethereum. If I'm not clear on a lot of this developers and users entering the space don't have much of a chance. This aspect of the space is actually pretty terrifying.
Web3 is hyped as much as it is because people have realized the internet is essentially whatever a handful of large providers say it is. If we're not careful web3 will just end up being a significantly less user-friendly and ridiculously inefficient implementation of what we have today.
I don't think it shows that! Running your own services, including say email/source control/infrastructure etc. used to be much more common; people started to pay the cloud not because it's super hard to run yourself, but merely because it's even easier to let someone handle it and focus on your own product.
I've also run my own nodes, but I still prefer to pay Alchemy.
However, I don't disagree with the thrust of your points.
This way I can hedge against the depreciation of my country's currency in an efficient way.
There are a lot of risks of course, to name a few: Stablecoins could suddenly lose their value; Dapps can be hacked and funds permanently lost;
For what it's worth I'm allocating a small portion of my "liquid" reserves in crypto (10%), only using stablished/audited dapps and avoiding Tether for reducing overall risk.
The moment someone buys a cup of coffee with bitcoin using the lightning network, don't they perform a transaction involving the real world?