First, for blockchain to work you need trustable sources. Problem is, when the aource is trustworthy, what added benefit comes from a blockchain?
Second, having a, theoretically uninterrupted blockchain from the first raw material to, say, a car would provide way to much insight into supply chains. I pretty sure companies do not want that.
Finally, and that is IMHO the haedest point to practically solve, you need to make 100 percent sure that the physical and information flow in your supply chain are never ever seperated. One single separation and your whole blockchain is worthless. And that risk is so incredibly high in the real world it's almost laughable. So, to make sure a given blockchain matches the physical product you need a trustworthy party to assure that. And then, what value does blockchain add?
Someday someone a lot smarter than me will find a use case. At which I will say how damn obvious it is.
I could see how this would be useful for medical device manufacturing, especially something like a pacemaker.
You can not otherwise too, right? A blockchain holds interactions/transactions not the data itself. Most blockchains are incredibly small in size. For example, the size of the entire Bitcoin blockchain is 215.84 GB [0].
Also, I see a possibility for licensing/DRM of some types of media IP.
That does not mean it needs to be distributed, though.
At the expense of time. So most real-world use cases (securities trading, vehicular networks, payments) fail when you introduce a 10-minute delay required for distributed confirmation.
For time-insensitive examples you've provided - supply chain and health records - the use cases work better, but who will dedicate the resources and mine the blocks to ensure that specific blockchain's survival?
Solution: blockchain smart contracts where code is law, more secure, trustworthy and transparent than any individual, bank, government or company.
Otherwise you have a synchronization problem between the upcoming blockchain token system and the existing government deed registry, and of course the government registry would take preference, and has a history of working just fine for lower cost.
This video is an excellent overview of this topic: https://www.youtube.com/watch?v=YxmXIgLEAIE
I haven't seen blockchain systems as being more secure or more trustworthy. I see them being overhyped, subject to lax and magical thinking, and full of theft of coins due to hacks and scams.
Also we are just talking opinions here, a lot of things seem impossible until they are actually here and in our everyday lives.
You might learn something.
As for the yacht it's easy, the ownership is transfered from your address to the buyers address on the government's blockchain. :)
The DAO issue [0] clearly showed that "code is law" doesn't really work. It's people writing cryptocurrency software and running the nodes that are "the law".
[0]: https://www.coindesk.com/ethereum-executes-blockchain-hard-f...
The blockchain can't (or at the very least shouldn't) overwrite legal infrastructure.