It looks exactly like Twitter, it feels exactly like Twitter (both the Web interface and the official app), and it's for tech-illiterate dumb-dumbs.

Only recently has an instance selector been added to the sign-up process of the official app, but Bluesky still markets itself to its users as the self-same kind of centralised monolithic silo as Twitter and Facebook.

Mastodon has a vastly different UI and UX from immediate pre-Musk Twitter, but people don't want to learn anything new. And truth be told, I've read from Misskey/Forkey users that Misskey and the Forkeys actually have an easier-to-use Web UI than Mastodon.

Also, Mastodon advertises the fact that it's decentralised with lots of instances to choose from, even though the gGmbH would rather want everyone to be on mastodon.social. This freaks people out.

Joining Mastodon is actually no more difficult than joining Bluesky in practice because the official app railroads everyone to mastodon.social without forcing them. But people won't know until they've actually installed and opened that app.

The only reason why Mastodon grew so quickly to such an enormous size in late 2022 was because it was the only alternative to Twitter that anyone knew, including those who pulled Twitter users onto Mastodon. The only other advantage it had over anything else was that, unlike Twitter, it didn't have Musk and uncontained droves of Nazis. Had people been sent to Akkoma or Calckey instead of Mastodon, it would have exploded the same.

Inb4 "How can people use e-mail then?" That's because everyone's on Gmail, and many think e-mail is a proprietary Google product.