It is Discord specific. Web crawlers can’t access messages. This means that instead of just using a search engine I now need to use a search engine and Discord. If we get a couple more of these services it is now a disaster.
IIRC it is “server” specific. So you still need to know which “server” would have the answer to start even searching.
While I don’t think message boards should move to it, Discord has a pretty good search feature, have you tried it?