People I spoke to didn't understand how a server and an app could be disconnected. They also didn't want to learn what the hell federation was and why people could register the same username for some reason. By the time you get to "it's like email" they've already downloaded another app.

Most people didn't want the Fediverse. They wanted Twitter that wasn't as shit as Twitter. Nobody cares about ActivityPub or ATProto, those are side notes to usable apps and experiences.

Bluesky also has more people go follow and interact with. Mastodon is for people who have a favourite Linux distro and people who follow people who have a favourite Linux distro. Bluesky is for everyone else.

Threads came free with an existing account. People downloaded it out of curiosity and were already signed in and set up.

The guy behind Technology Connections is on Mastodon and has explained several times what terrible consequences having more than a few friends follow you can have for usability. None of these apps were designed for a million followers, human moderation falls short and automatic moderation doesn't work. Every server has a different view of existing comments so they'll think they're the first to make a certain reply, causing a horde of reply guys to all say the same thing. His complaints are very valid and I don't expect him to last long on there, but he's doing his best to stick around. If he goes, I'm sure at least a few people will go with him.

Platforms like Bluesky have it easier dealing with moderation and are willing to use automatic moderation. It's hardly perfect, but it works better than not moderating anything until a report comes in.