The technology isn't the difficult part though. Will miners replace PoW with PoS? What will they do with all the GPUs and cheap access to electricity they've invested millions or billions in? The social aspects transition will be immensely more difficult than the technological aspects.

But I do hope that, somehow, all those miners will just... accept the move to PoS and turn off their mining farms. I just don't see it as extremely likely.

As I wrote in another comment, the miners are not really in control once there is an alternative solution.

They can continue using POW (if they manage to coordinate an independent self-destruct mechanism override) however they cannot force the actual users (private individuals and infrastructure providers) to do so.

If miners don't manage to capture a significant fraction of ETH value in their hypothetical ETHPOW chain it won't be worth their effort. Buying a GPU for mining now caries a significant business risk and prices are already declining.

PS: There are billions of dollars already staked in the (currently empty) POS chain.

Well, we'll see I guess. I certainly hope you're right. But PoS has been "right around the corner" for the last half decade at least, so I'll believe it when I see it.

I do wonder what miners would do with all their hardware and infrastructure tho. Presumably they'll all just move to another cryptocurrency and nothing really changed, etherium got a little cleaner while bitcoin or whatever got a little dirtier.

A sensible approach :)

Let's hope that POW turns out to be a very brief (in the great scheme of things) peak of human creativity / stupidity.