I think the reason Lemmy took off is because it's decentralized and a single person or corporation can't easily enshittify it to make stonks go up before jumping ship with their golden parachute. Tildes being invite only also really killed any chance of really growing imo. It was the same mistake Google+ made. I never really heard of any of the alternatives other than kbin since they didn't have the same voice as lemmy and kbin had in the whole reddit API enshitification and death of 3rd party clients

Kbin doesn’t seem like it’s going anywhere. The repos are dead (one commit in the last two months, written in php which is not promising for new contributors), there’s really only one instance of it, and I don’t know of any communities hosted there. There’s also no app support, which is crucial for me to actually use the platform. The concept is good so I’d love to see it continue, but I also wouldn’t invest anything in the platform at this time.