I mean, you can still transact. As long as you have your private key, you can transact. For example, there is going to be a "Proof of Work" fork of ETH after the merge. Price will dump on day one, but it will be there, and will tick away, and you'll still be able to move your ETH on both chains. But one will be considered canonical, because the community has gone with it.

Same thing has happened to Bitcoin multiple times. BCH, BTG, etc.

I think it's just as simple as "if you want to interact with people through software you have to use the same software as them." Nothing controversial about it, its just that the interaction isn't chatting over telegram, it's transacting.

There's nothing stopping you from selling your ether to someone who wants it and deploying that capital on something else. Or ignoring it and forking the chain and keeping your fork ether. "But it's valueless" I hear you say, see my above paragraph for the answer to that one.

This commenter here is right you know. They (Ethereum Foundation) decide what the 'trademarked' Ethereum uses and if you are not on whatever they ultimately move to, well your money is unusable and locked. PoS is an increased risk of censorship and it is quite possible for regulators to even tell validator providers to censor addresses if they want to be compliant with regulations.

It is the re-centralization of Ethereum and will be made worse with Proof-of-Stake.

There only needs to be a single miner that uses PoW and you can freely move your funds to other wallets. You can even start the miner yourself.

So no, your funds are definitely not lost. You might be the only one connected to the "network" but wasn't this the promise of cryptocurrency decentralization?