When I first joined the CiviVerse, there was one place to go to get questions answered, see previous discussions, and meet fellow community people.
Now there are several places. But the Stack Exchange doesn't facilitate discussion, or trading of ideas to produce a single unified solution: people offer either a right answer or a wrong answer, and the asker either accepts it or rejects it. But only a single answer wins.
Additionally, I can't easily find a list of recent discussions in a different area. Someone may have an idea on how to improve things in a rarely used area - but where can they take these ideas where they will be easily seen by anyone interested in that area? GitLab? But then that's segmented from the Stack and Chat communities. In the forums I could go to a section and see it, and tagging doesn't work nearly so well.
Some conversations take place in chat. But if I encounter a problem, and ask it, there's no easy way for another person to google and come across the same problem. It's nearly impossible to get anything from chat hiatory, which is where the experts typically hang out. So their knowledge isn't as widely visible.
I feel that the forums offered a great bridge between all these options, and I only needed to keep track or be involved in one community. Now there are several.