Hi @autumn,
this is what I think since a long time. When I decided to go with october cms back in 2016/17 this forum - besides great documentation - was a main reason for my choice.
Back then I wanted to build a website/web app only with some outdated php knowledge from the nineties (and finally did). So I was (and still am) kind of a beginner. My first try was with bolt cms. The start was easy, basic documentation ok. But especially as a beginner, even the best documentation often doesn't make one get a grip on how to actually accomplish some desired functionality the best way. This is generally where a vivid and helpful community comes in handy. And bolt's was on slack. The developers answered questions fast. But it is basically a chat as discord is. multiple topics get discussed at once, answers get buried first and finally lost. And google won't find them at all.
The october cms forums were so helpful. Long discussions which helped me to find working ways to deploy - and so many other people who had the exact same problems of understanding this or that and helpful answers easy to find. Often enough I only had to copy and paste the answers code - problem solved.
Then came slack and now discord. And I really don't see any benefits of these for support and technical discussion. Maybe I'm too old (47)? But I guess on discord the same questions get asked again and again on discord. And people spend their precious time to give the same answers over and over. And no one benefits from it, except the one guy who asked. Entirely different with a forum. Questions and answers and discussion stay forever. Well orderd by topic and easiest to find with google.
Forum topics are also valuable content in terms of google serps. Wasted oppurtunity with discord.
I used to be admin of a forum a few years ago. Sometimes users asked questions which obviously were also of interest to other users via email. I never answered their question via email. I always asked them to ask publicly on the forums again. There I gave the answer. This way others could benefit from it. Even ten years later.
Discord or Slack for discussions and support within a community around a software are like email in my opinion. It helps almost no one (ok, it helps exactly one) to solve their problems. And newbies or people who are about to decide which system to use will get the impression, that a community is small to non existing and turn their backs. I would have done so back in 2016 if this forum would have looked so abanandoned as it seems now.
my 2 cents,
Chris
p.s: Funny you mentioned flarum. Actually I was googling whether by now there are integrations of Flarum with october cms. This way I found this topic :-) So the best would be to cancel discord for October community support, migrate this forum to flarum and integrate it with october cms ;-)