While the comments in some of the larger subreddits can be less than engaging, I think there's still a lot of value to be found in many of the more niche communities that are well moderated.

New reddit ('the redesign') is a disaster, and old.reddit.com + RES is what makes the site usable. It's going to be a tremendous loss if (when) they are no longer available.

lemmy.ml (no affiliation) looks interesting and it's one possibility for where to go next, but there is currently very little activity there for some of my interests.