So the last threat is probably the biggest threat, and it's that developers are myopic about Mastodon to the detriment of the rest of the Fediverse.
There's lots of Mastodon clients. But most of these clients do not support the likes of Akkoma or Friendica despite both those servers having API compatibility with Mastodon.
Even worse, some of these clients don't even display messages from non-Mastodon servers.
This developer myopia actively breaks the intentions of the Fediverse.