I believe miners wouldn't, because while they might technically coordinate their efforts in deciding which version of a cryptocurrency to mine, they aren't pooling their resources and representing themselves as a single entity.

That's partly what makes these individuals an unincorporated organization.

ETH no longer has miners since the switch to PoS. There are now stakers, validators, liquid staking tokens, block builders, ... it has gotten a lot more complex than it was before.

What? Why would they be liable? The whole point is the liability in a partnership is shared between the partners: that is the entities that own the partnership.

Miners (staker?) aren't partners in the DAO: being a miner doesn't make you an owner of anything, anymore than being an employee or contractor to a partnership in the real world would make you liable for the actions of your employer/client.

They don't cooperate for profit, they compete with eachother.

Everyone in a mining (or staking) pool seems more likely to count as a general partnership.