Mastodon excels in updates. If a niche is alive on Mastodon, then you will get news from it before Lemmy. Especially in infosec, or (if you are from Europe, especially from Germany or the Netherlands) local news.
In a way, shitposting is also freer on microblogging, without Threadiverse's pigeonholing into different magazines/communities

The discussion may have worse UX. Only selected alternative frontends (like phanpy.social) have got nested threads like here and until recently, replies were delivered only to replier's follower instances, resulting with users not seeing all the discussion and inconsistent threads between instances.