Oh so you're saying a central authority can declare your currency worthless at any time? Good to know. Sounds very like a central bank issued currency though?
This is a purely optional part of the crypto ecosystem, so I don't see how it's an argument against crypto in general.
One can also burn tokens, just as one can burn cash, but we don't tend to hold that against either systems since it's purely optional.
Stablecoins are literally central banks. Decentralised coins are literally decentralised central banks. Bitcoin's algorithm is a central bank.
It's literally in USDT contract [1], see line 264. USDT is implemented as a contract in several other networks like ETH and has a blacklist. So every USDT operation is a record in ETH blockchain that calls one of the methods (like "transfer" or "add to blacklist").
[1] https://etherscan.io/address/0xdAC17F958D2ee523a220620699459...