I suspect most people aren't subbing/following communities on Lemmy. So post the community or topic you want to see pop off. And reader(that's you) if you are interested in that community click the link and follow it.
I kinda wish we’d merge them… which I know goes against the grain of how the fediverse is supposed to operate.
Not necessarily:
One of the advantages of a decentralized platform like Lemmy is the ability to create parallel communities on the same topic. “You don’t like how a community is being moderated? Go to another instance and start your own community!” (with or without blackjack and hookers)
However, this is a double-edged sword. The creation of multiple communities on the same (or similar) topics can also fragment the userbase, leading to very sparsely populated communities.
I think it only makes sense to have multiple communities on the same topic if each version serves a specific niche or has a unique moderation style. I think most of the examples you've given would be suitable for consolidation into two or three communities.