It is absolutely used as a forum. It even has forum features built in.

Unfortunately a lot of places use discord for things that forums used to do - bug reports for software, collecting feedback, even troubleshooting and tech support.

I imagine this is because discord servers are free while websites require money to maintain.

no I mean people or organizations using specifically discord as their sole support platform and the janky threads feature in place of a real forum, but a lot of useful info buried and not pinned in the general channel and whiny assholes that get mad at you for not searching on the shittiest search implementation known to man which still gives you multiple or all channels of results when you single out specific ones. The worst part is when you search something and it gives you posts from a single thread, out of order as well as interleaved with other threads.

Then you pick one but its useless and when you go back it refreshes and gives you the list from the beginning with slight order variations to keep you on your toes.