It seems like any platform that features link aggregation is soon overrun by bots and self-promoters trying to drive traffic, and pages and pages of link posts versus pages and pages of people talking.
Are there any lemmy instances or other defederated networks that focus on Q&A, niche communities, and people conversing, instead?
Usenet still exists, and there are tons of old fashioned forums online, some of them good. Lemmy has its attractions but it is trying to be Reddit and maybe succeeding a little too well.
Depends what topics you are looking for. They tend to focus on particular niches. Example: home-barista.com, for coffee nerds. I’m not a regular but have posted there a few times.
I have thought for a while that the next “reddit” should be usenet with a client having advanced filtering, local scoring, etc. Maybe where the client reports to/reads from a shared spam database.