There's some nice search features: https://support.discord.com/hc/en-us/articles/115000468588-U...
And on top of this I'd push the Discord to use forum channels if they do not already https://support.discord.com/hc/en-us/articles/6208479917079-...
I still think it's a bad substitute for both documentation or a web-searchable forum. I can't use a web search to find results on Discord. I have to log in to a Discord server and use Discord's search so it's a separate set of steps from the web search I initially did when I started trying to solve my problem.
Once I grudgingly jump through those hoops, if the server admins and users are actually using forum channels, I might find reasonably structured results, but they often aren't. When I have a technical issue with a software project, I would like proper docs, then a proper forum (Lemmy might be a good option as of summer 2023), in that order. Real-time chat, whether it's Discord, IRC, or Matrix is a distant third.