But you’re seeing the effect of having multiple niche communities right now: they are mostly dead. Quite simply, there is not a sufficient user base to keep niche communities active. Along with lemmy search being as bad as (maybe worse than) Reddit search and the issue of having niche communities dispersed and duplicated through multiple instances.
It looks to me like the numerous, inactive niche communities we have now largely sprung up during the Reddit protest. People came over her for a few days, created a whole bunch of niche communities, but then those communities never got traction. It seems most users quickly went back to Reddit, and now we have all these little ghost towns.
“Solutions”:
I see a few fixes that may help this issue, but I think the largest barrier is the size of the user base. There probably are not enough users on lemmy right now to have a bunch of active niche communities (edit: even if other issues with connection users were fixed). From that perspective, as others her are saying, the practical solution seems to be to keep your activity to broader communities that cover the niche topic, and use those communities until there seems to be enough discussion on a niche topic to warrant a niche community.
Other fixes:
Aggregate communities: this is something that has been discussed on lemmy, but I haven’t followed in depth. But essentially, being able to have a “multilemmy”, which aggregates communities across instances. Eg, there may be 10 different “model_trains” communities spread across 10 instances. This means that there could be enough discussion across those 10 communities to have one active niche community. But there isn’t an easy way to get users to participate in one particular community/instance combo. Some way to aggregate those communities could really help connect users and content. I get the impression that we are unlikely to see this kind of feature any time soon (but like I said, I haven’t been following this issue).
The other solution is finding a way to hide/remove/mark inactive communities. There are lots of niche communities with zero or one post from months ago with no active owner or moderator. It is up to the instance owner to decide how to deal with those communities on their instance, which means there is not going to be consistent handling of these communities.