idk. Google used to automatically highlight pages that you landed on then stopped your search, which indicates you got a good result. They basically scrapped that, though, since their advertising arm wanted people to spend more time searching, running more queries, to get more ad impressions. Google literally sabotaged their own search algorithm to increase "engagement".
It's not scalable. Sure you could have humans comb through the most common 1000 or so results, but there's got to be billions of unique searches every day