Maybe advertise your idea to the right people.... But you're right. Starting a new communitiy takes some effort and more than one person to get things rolling.
I miss some more focused communities where people can ask for advice like relationship_advice or problems in the bedroom. Or stuff / funny stories from other peoples lives. For when i can't sleep at night. Or i want to assure myself that i'm not the only one having problems.
It sounds like you might be referring to communities rather than instances. If you don't want to mod it yourself you could ask in one of the request communities and soneone might choose to start it. Try doing a search for 'request' on whichever instance seems like a good fit, and you'll find one.
Hi there! Looks like you linked to a Lemmy community using an URL instead of its name, which doesn't work well for people on different instances. Try fixing it like this: !newcommunities@lemmy.world
Just start one (a community, that is). There's not some marauding band of trolls out there, waiting to give you a hard time. If it's niche enough, it'll be a highlight just to see someone-who-isn't-you post something!
I wouldn't mind creating one, but thinking ahead there may be new users who are looking for certain communities but don't have the experience to create or mod one themselves.
This could help get things going faster and may give ideas to the people that are happy to do so.