DeFi was supposed to stand for "Decentralized Finance". If they can be shut down, they're not decentralized and don't deserve to use that name.
You are missing the point. It doesn't matter if they call themselves they are decentralized or not and what they deserve.
It can very easily happen that domains (and everything else recognized as their resource) are seized, which will put them in the same group as mixers.
The pressure is increasing, and Bitcointalk admin & members decided to close their eyes and turn their heads.
However, the front end can be banned, and the developers can be punished, like tornado cash...
But the smartcontract can still be used , their api is still running in ethereum blockchain for those who knows how to use it.
In that case, anyone who starts a similar service or one based on this protocol is against the law and risks sanctions.
Isn't that a similar scenario where the mixers are currently?