That’s easily abused. Search engines before Google were pure keyword search, but those were quickly abused. People just made websites with all types of keywords just to get on top of search results. Google’s PageRank fixed this - temporarily. People were quick to abuse it too.

It doesn’t matter what you try to do. Somebody will figure out how to abuse it.

But to do that, the algorithm has to know the right answer in the first place. Meaning a human has to tell it what’s right and what’s wrong.

Have you seen Google’s generative AI tests? They’re trying to do exactly that and it’s mostly useless.