you seem to deal in absolutes, which are nothing like my experience.
i can only give my opinion on my experience, and that experience is coloured by over 25 years of programming and support of complex systems.
in all that time, the defacto best solutions for problem solving were not rolling chat channels that are unfiltered and very easily spammable and rendered unusable without quite diligent policing. not once, not ever.
discord has a purpose. i don't actually know what that purpose is, but it ain't as a viable and workable support medium for issues that may come out of a mod or a program or whatever that needs slightly more thought than "have you turned it off and on again?"
we had this years ago with irc channels, some of which still exist, and are still used, but they are policed because they have to be policed and despite that, they can be disrupted on occasion and rendered unusable for a time.
I will give you an actual advantage that this suite of forums has over discord or any other rolling chat medium. i am finding answers to issues i've encountered recently, that were worked out 12 months ago.
good luck doing that on a discord where sometimes you can't scroll back 24 hours. and even if you can, the answer you seek may be buried under tons of random gibberish.