When ETH go PoS, where all miner will go ?

When ETH2.0 come and become a PoS network, miners will become unneeded. Yet their mining rigs won't disappear, reselling sounds unlikely too.

This means they will have to switch which crypto they mine. What do you think they will switch to ? Would they mostly go bitcoin ? Making it jump its hashrate. Another particular coin ?

Or do those huge farms also run those algorithms which constantly switch which coin they mine depending on profitability ? And in those case, which coins are used generally ?

I'll admit not being really knowledgeable on mining culture, and it's a lot of questions.