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.

Havent heard of exploding-heads, I guess thats a good thing?

That is how mastodon handles groups currently, as proper group support is still cooking. It is now on mastodons radar and hopefully that’ll lead to better support in the very near future.