Because Lemmy is new and doesn’t have many users some of it’s communities are dormant. And I have a lot of free time, so if you would like to see more content on a sublemmy but don’t have the time to bring more content yourself tell me on comments down below, maybe I can improve things somewhat.
In my opinion simply crossposting stuff from reddit is not a solution (I’ve seen you’ve been doing it with pixelart sublemmy). I think that lemmy needs more discussions under posts rather than more posts. If there is a discussion, there is a community. If there is a community, cool new content will come. I myself created !diymusicgear@lemmy.ml, and so far I’m the only one who creates posts there. I get some upvotes here and there, but it does not help to build the community. It’s not hard to find content on the topic, it’s hard to get involved
You can’t expect newcomers to stay on the platform without anything to discuss. This way when new people arrive they will have stuff to be engaged in. We don’t have the numbers to make tons of cool and interesting content, so this is the way to go. Think of it like playing games on Linux with Wine. It gives you access to certain content types you wouldn’t have had access to otherwise. It made switching to Linux possible for some people and over time community became big enough to attract some developers, and playing games without Wine became a possibility. Given enough time same will be the case with Lemmy.