Mastodon's UI is horrible. At least for people who never used Xitter. Why did a new company (at a moment of Mastodon initial release) copied already ancient and by then pointless limitations? Character limit, linear feed, tags in text, no advanced formatting etc. And then there are registration problem (where to register), the retention/safety problem (what if a benevolent admin of your instance nuked your account, now what?), the discovery problem etc. I'm permanently baffled at the decision process of Mastodon developers.