It's difficult in general to know that the results you're returning are definitely not what the user wants. You're not seeing them think that they know better t

It's difficult in general to know that the results you're returning are definitely not what the user wants. You're not seeing them think that they know better than you, you're seeing lower confidence results. Perhaps search engines could just not show you lower confidence results, but then you risk making it impossible to find certains kinds of content, and you forgo the rarer, but still extant wins, you get from showing those results. Users can generally tell when results aren't relevant and will reformulate anyway.