Interesting. Not that long ago we moved everything out of Confluence into Google Drive because GD search worked. Confluence search was horrible to find docs I knew were there.
That's because no-one bothers to read the documentation linked in the search field.
Protip: Use wildcards extensively. Differently from Google, Confluence search considers keywords entered to be limited by word delimiters. so foo matches only foo, not barfoo or footer. Use them with some wildcards, foo, and the search results starts to make sense.