This is a really good insight. One thing that might have helped years ago would have been to build in more tag-specific features so that communities could form around, say, Ruby or AWS. Collectives seem like a step in the right direction. Only it got off on the wrong foot and doesn’t feel like a fully baked feature. Another option would have been a Reddit-style sub-stack feature. (Too late for that name though.)
I’m not sure we knew what we were doing when I was on the CM team, but we did try to push for features that we thought would help. Never seemed to be the confluence of resources and focus necessary to refine anything, however. 