I mean - pre google had the problem of "these two webpages are both about how to take care of your dog, but which one is higher quality?"

Backlink ranking was/is a reliable heuristic to answer that question across virtually all topics.

So I disagree that the "problem was not about quality."

Spam/scammers will always be in whatever landscape there is, and I agree part of what google does it keep them at bay.