1. Mastodon is disproportionately a self-selected group of very active social media users. The people who cared the most about the state of Twitter were most li

1. Mastodon is disproportionately a self-selected group of very active social media users. The people who cared the most about the state of Twitter were most likely to care enough to leave Twitter. 2. Twitter has a much higher number of fake and bot accounts. 3. Twitter is much older and thus has a lot more accounts that have been abandoned or are relatively inactive, whereas Mastodon has seen a recent, large influx of new users and thus has a higher proportion of currently active accounts. Also, anyone with a longstanding Twitter account has probably collected a lot of followers and followings over the years who they no longer care much about. 4. Mastodon has attracted specific subsets of the Twitter population, rather than attracting broadly from the general Twitter population. For example, I've seen that software developers have migrated en masse. Thus, there tends to be more activity, because you have a relatively large collection of like-minded or like-interested users. It doesn't feel "lonelier" on Mastodon despite the overall vastly smaller user base when the people you know all happen to be on Mastodon. In fact, my Twitter feed is now a pretty lonely place. 5. As a result of all of the above, Mastodon users feel more comfortable posting and replying. More people you know and like, fewer people you don't know and don't like, not many "drive-by attacks". And Mastodon has technical limitations preventing a lot of the typical Twitter nastiness: no global search, no quote tweets, etc. 6. There are a lot of famous people or entities on Twitter, and a lot of Twitter users are there to passively follow the tweets of those famous people or entities. Whereas there aren't many famous people or entities on Mastodon, and people are generally there for the purpose of interacting rather than for passively following. Overall, Mastodon now is somewhat similar to how Twitter was during its early days, before all of the ultra-famous people joined. Smaller, cozier. Like Cheers, where everybody knows your name, and they're always glad... sorry.