So you use something designed for gaming to run a technical community, and when the search wasn’t built to handle highly complex or technical queries you complain?
It doesn't work for gaming either. I mentioned this in my comment.
Slack is a worse product in almost every way, but it does have better search than Discord if you pay 850 yen per person per month. Do you think that e.g. the Sorbet slack or the Zig community discord should pay 850 yen per person per month for any random person who wants to discuss their open source project?
Why not use Slack?