My biggest problem with Discord is still more related to support communities (what would have previously been a focused forum or subreddit) moving there, and the subsequent lack of archival of topics and answers for future reference.
This has actually been fixed in the past ~6 months, and quite nicely.
They added the concept of a "forum" channel, where you can have individual support questions, and each one has its own thread that addresses that specific question.
Better yet; the search box and the "make a new post" box are the same box. So if you're starting to ask your question, as you type, it's filtering previous questions based on the words in the question you're trying to ask.
The Zig programming language community has a very active Discord, and they use the forum mode. I've searched for questions I feel "certain" someone else would have asked (like how to convert a `[]const u8` to a `[255]const u8`) and rarely can get Discord's search to find something relevant. Thankfully, the community answers quickly anyway.