No, the validators are anyone with a stake in the system, not just the Ethereum foundation and friends.
The parallel with Bitcoin is quite strong. You can run a Bitcoin node without running a miner and verify the chain but you don't get rewarded. You can run an Ethereum node without staking and verify the chain but you don't get rewarded.
I am asking about the people with the power to declare that people who put up the stake were dishonest in their validations.
The key innovation in modern POS systems was figuring out how to do this, it is a solved problem.