Sublemmy isn't a thing. It's community or c/

Seriously, it will help you a lot to stop thinking like this is reddit, because it isn't, and trying to treat it like it is leads to this kind of thing.

All those niche subs? They didn't start out there, and weren't useful for the most part because even with the reddit size user base, there weren't enough active posters to keep them relevant.

Lemmy is smaller and more distributed. Currently, having ten similar but not exactly the same C/s on the same instance is just going to make discovery harder for each of them. And, it dilutes the content making each one seem unpopulated more than they otherwise would be.

I promise, I'm not bashing you with pedantry over terminology! It's about the already established culture within lemmy from before the current migration being respected, and shifting the way we think about how we interact with the fediverse.