Tampering with Bitcoin’s censorship resistance would be extremely difficult. It would basically require buying off or influencing a majority of developers and somehow changing the consensus rules or mining algorithm. Considering how decentralized and transparent the system is, that’s almost impossible to achieve.
I still agree with that, from the point of view of now (2025).
But you don't need to bribe developers for that. Just hire developers to create your own variant of the Bitcoin client, for example with a blacklist mechanism, or an anti-CoinJoin feature. Then convince miners that they should run your client, because otherwise the US/any other government would dump all their coins, Bitcoin would crash, and your mining hardware would be worthless.
Impossible? Yes, if the following "censorship resistance agreement" in the community still is strong:
1) cypherpunks are still influential in the Bitcoin community and among hodlers, and continue to advocate for censorship resistance.
2) miners are following cypherpunks' decisions because they believe that cyperpunk's views are essential for Bitcoin's long term health
3) and the "passive" users (BTC and ETF holders who are only in "for the profit" and don't care about censorship) are not strong enough to revert the "cypherpunk-miner consensus".
If any of these three elements begin to weaken, then the problems I mentioned in the OP
may appear. They don't have to. But it wouldn't be impossible in this case to break the "censorship resistance agreement".
Regarding solo mining, I think it's overrated as an anti-censorship mechanism. I have read elsewhere that the best strategy is to join a small to mid-sized pool.