The biggest problem with Discord is that its an information black hole. Its not properly searchable and not indexed by search engines.
Discord is fine for casual chat, but horrible when used for forum-type discussions and even worse when used for documentation.
You see the same problems being discussed and solved again and again, but you cant just "link" someone the solution like you could with a forum thread cause its spread out over 3-10 chat messages that are interleaved in-between other topics being discussed in the same room
Anything of long-term value for the project (forum-type discussions, documentation etc) should not recide in Discord