Not sure if a percentage growth of subscribers is the right metric - a growth from 1 to 3 subscribers looks much bigger when expressed in %…
I visited one of the communities listed, and it literally only had 3 posts - a welcome one and two pinned ones. All by the same author. That’s not exactly what I’d call a fast growig or trending community…
A lot. The way I curate my feed is I subscribe to communities that I’m actively and significantly interested in and block all of them that I don’t see myself ever wanting to check out. The rest are places that I might want to see, but maybe not all the time. This way I can filter by Subscribed to see a very focused feed and by All if I want some more randomness, but still without topics I’m really disinterested in.