There's no need to make a new community. There are plenty of communities that already exist solely for finding chat partners or to post personals. However, they aren't active and when people do actually post they get zero replies. The problem isn't the communities.
I can't be bothered atm (eating pizza is far more important), but I can edit in a few later on.
Edit: Alright, as promised, here's a list. Not all of them fit OP's specifications, but all are general discussion, erp, dirtychat, or personals communities. You'll notice that in almost all of them most posts go completely unanswered. Also, don't use native Lemmy ui for community search, use Lemmyverse.net .