It's true that there are still exchanges that are still listed and the government can't do anything with them, they can order certain exchanges to take them down but they can't dictate everything.

Governments can't do anything directly to the project but they can always target exchanges to take them down or create laws restricting users from owning as any crypto starts to get regulated. Privacy coins may continue to exist but there is no guarantee that users will continue to use them as the government itself will do whatever it takes to restrict users from acquiring these kinds of tokens.

if it's truly 100% decentralized, any sanction won't affect it because anyone can still use it. The price of privacy coins is based on demand and supply, so since the sanctions are primarily focused on privacy coins, it may drop the price due to panic and reduced demand. IMO holding privacy coins long term is not a good option as government always enforce KYC submission which will eliminate privacy issues.