I disagree about the power shift. Twitter holds a complete information monopoly over all its content. This means they can make hostile changes, such as forcing

I disagree about the power shift. Twitter holds a complete information monopoly over all its content. This means they can make hostile changes, such as forcing a login in order to view public content, without much repercussion. If Twitter were to ban me, I would be completely cut off from all of my friends on Twitter. You can't easily move away from Twitter, because Twitter is a huge entity with swaths of content and users already on it. On the other hand, Mastodon instances have only a fraction of that power. They have control over information only that is on their instance, in a world that contains thousands of such instances. They are tiny entities holding control over small fractions of the content available in the fediverse. If a Mastodon instance started acting hostile, people can relatively easily move away to a different instance. If my Mastodon instance were to ban me, I can sign up on a different instance (or host my own) and still keep in touch with my friends; unless my friends used the same instance and the owners broke federation with the instance I moved to, at which point a lot of people would probably want to move away from that hostile instance immediately.