Scott Feeney on his blog post, "Four Twitter Features Mastodon Is Better For Not Having" points out several negative aspects of Twitter's design that the Twitter-like Mastodon does not have:
If you’ve gotten in an intense argument on Twitter, you might dread this “So-and-so liked 10 Tweets you’re mentioned in” notification. It tends to mean someone went through and gave kudos to every person arguing with and insulting you. It’s stressful to be pinged over and over with this—which is exactly why we’re all tempted to do this to people we think crossed a line. In doing so, we, again, increase the reach of content we dislike.
The other features he mentions are quite refreshing too.
Also, as of today Mastodon has over 1 million active users! 👀