The bubble has burst, none of the fun communities I subbed to when I came over have any active users left anymore. It's all the same 3-4 people posting news and rhetoric.
I know that Lemmy has a fairly small range of interests, but I don't know of any communities that were once highly active and have since gone dormant.
He said the bubble has burst and there were fun communities when he first came over that are no longer active. I'm asking for an example, because according to my recollection, there never really were active communities outside of the topics you mention.
That's not specific (or true) though, there are plenty of active niche communities, especially those for localities. Which communities would you like to be more active?