I always do a search by key title words.
My issue is that duplicate posters do a search by not selecting title at all. They’re relying on the goodwill and intelligence of the original poster and subsequent ones to incorporate good keywords.
Nailing a duplicate post by title keyword is easy. But what I suspect is many don’t even click “titles” rather than leaving the defaulted “Keywords” which is always incomplete.
To summarize, keywords will ALWAYS be incomplete.
Titles will not.