That was in reference to Discord, not Reddit. Reddit is searchable ~fine via Google and its internal search (but I wouldn’t be surprised if they at some point break that in exchange for more forced signups and to prevent “AI content theft” like Twitter).
An anonymously searchable alternative to Reddit's search function is PullPush, an archive site independent of Reddit.
It has full-text search and will even search through deleted and removed content.
Main site: https://pullpush.io
Frontends: https://search.pullpush.io, https://ihsoyct.github.io