I think the ideal would be not how to make it “like Reddit”, but how to help niche and smaller communities have more members. Unfortunately, I think the easiest way is just to get more users to Lemmy in general.
It is not just niche topics, I find quite a bit of things that are not (in my opinion) niche, yet there is very little participation in Lemmy. Take for for example Postgresql. By now it is one of the most widely used databases yet there is a minuscule number of posts and users in the related communities.
Another example. Just did a search for largest communities in Reddit… One of them is music with an estimated 38 million redditors. In Lemmy the largest two music communities seem to be 9.9K (!music@lemmy.world) and 18.9K (!music@hexbear.net). That is an astronomical difference for something that is as mainstream as it gets given the broad topic.
I think the best each one of us can do is to participate and post as often as possible in the communities we would like to see grow.
Agree on this 100%. When I first found Lemmy I had no idea what instance to join, why it matter, or… why it really didn’t matter all that much… It was just confusing… and the first instance I joined ended up closing… which was less than an ideal experience as it was without notice and the instance just disappeared. Took me days to even find out why they had closed. Then took me several more days to find the next instance to join.
Federation is both a weakness and a strength in that there may be people who get turned off by that initial complexity.
Then, some people who join may see low volumes on communities they care about and end up not joining.