Is there any hope? Or is it inevitable that big corporations will take over what started as a way to escape big corporate platforms and to focus on real communities and discussions and replace it with a toxic shithole pumped full of ads?
If a corporation aims to purchase an instance, all the other instances would let them know they will vote to defederate it as soon as the purchase is finalized. That ought to make them change course.
That's not how meta's going to do it; they'll start their own (with blackjack blah blah) that has better servers, better design, and other stuff real money can buy until theirs is the default. Then when they have the vast majority of users, they'll start throwing their weight around and others will be pressured to comply with the 'standard' they set.
Other instances can always wall them out from the beginning. Sure, they might have better UI/servers, but if they're never federated they've essentially just created another Facebook.