site ranking is not a “solved problem” - google tries to solve it all the time and yet finding anything other than trending or popular stuff still takes more than several attempts (and often doesn’t even result in best results).
Google has a set of contradicting requirements for the interface they've got on their website.
From one side it's along the natural-language interface from Alexa or alike; from the other side it's an interface of search for people who generally need access to information.
If Google exposed interfaces similar to Elastic Search - the search would never be an issue anymore; but it would not be easy to use by the users.
The one reason Google is competitive is due to them taking advantage of the cheap labour that keeps track of ranking manipulation.
Luckily most of the search problems have nothing to do with ranking manipulation.