I agree. This is something that I'm not sure people who go into crypto fully understand with the resulting consequences. The FED is basically printing money and I can understand people who don't agree with the inflationary mechanism that is built into fiat currencies - this is one of the main criticisms of the fiat system because it's debt-based.
On the other hand, having no means to get taxes (because of anonymous currencies like Monero and anonymous wallets) and having no control over the currency is a safe way to a plutocracy. Some would argue that we're already living in a plutocracy, but currently we have democratic ways to intercept (although we're currently not good at exercising that power). But if it's technologically impossible to intervene, there's not a lot of ways to fix this.
Good article about this [1].
[1]: https://medium.com/@dionyziz/blockchains-are-inherently-plut...
But now, they can hide enormous wealth in an untraceable way on many wallets. It's not entirely new - tax evasion is as old as taxes - but it's easier and accessible now for large wealth that was more difficult to hide in the past. If crypto stays legal, you can't control this aspect.
> buying things directly with crypto will become more widespread
I'm expecting this to be the case if adoption happens.
The runners-up can just launch their own $hitcoins and be kings in their own domains.
Then what is Web3? Cryptocurrency has been a thing for a little while now, surely Web3 isn't just that but with a new name. I think the idea is that applications can in some way utilize the blockchain to form a new type of application for the web, but I've yet to see any useful application ideas that truly benefit from a blockchain.