What made everybody move from a corporate social media platform to another corporate social media platform instead of the fediverse?
After all, the Fediverse and Activitypub is much more mature than Bluesky and the copycat AT protocol or Threads and … whatever they use.
Its easier to just sign up and find everyone immediately, than to go learn what are instances and which one should you choose to make an account on, and then go and learn how to find other people that are not on that instance, or how to check do they have a mastodon account at all, then go and learn how to XY.
The “go and learn” is something that people, most of them, just don’t want to do. If you need to learn how to use something, this is the first indicator of a bad user experience. It should be obviously easy for a new person to get around.