Honestly, lemmy and the fediverse as a whole will have natural growth and thats fine - mastodon has been around for like 8 years and is only recently getting a small amount of attention and mainstream usage. Like take the long view - like the really long view like 15 years from now. It’ll probably be huge, but until then we will just share memes and have a good time discussing stuff.

At what point do you end up re-inventing c++?

Theres also misskey, calckey, and plemora

Pixelfed just implemented an instagram import feature as well!

there aren’t that many kbin instances out there

This is also due to its age, its only 2 years old and only just recently gained more than 1 contributor to its codebase. When the reddit migration started about 2 weeks ago, kbin considered itself still in alpha; with lemmy in beta. As the software matures, more instances will pop-up as admins gain confidence in it.