Clive Thompson provides a thoughtful look at how Mastodon is different from Twitter (and most other platforms):

Perhaps even more important than the design of Mastodon is the behavior established by its existing user base — i.e. the folks who’ve been using it for the last six years. Those people have established what is, in many ways, an antiviral culture. They push back at features and behaviors that are promoting virality, and they embrace things that add friction to the experience. They prefer slowness to speediness.

Mastodon will never really be a replacement for Twitter. It’s a subtly different place. You see less of the massively viral, you-gotta-see-this posts. You see a lot more murmuring conversation.