I always feel like whenever someone complains about fedi not being fully decentralized because they perceived too many instances as being held under a single place, they miss the point a little bit in terms of prioritizing infrastructure over user governance.

Aside from the potential disasters happening at them, it just really doesn't feel like a problem if most people are hosting an instance on a popular cloud platform. These are companies that are just providing infrastructure, and as long as you aren't trying to abuse their network or spread anything that they consider to be harmful, they won't really care.

Instances operated under Home and business ISPs aren't particularly immune to this either. And can still cut off an instance if they decide to.