Hmm, but weren't you already rating websites by clicking on the search results before? I don't see how that changes the game - and I must admit I don't know much about SEO - but in my view we were always rating results and that was influencing the position. Now they make the linking obsolete or at least less important signal... that's good? It means that relevant content is going to be surfaced to the top. Win-win honestly (and yes, Google will continue to use users-generated signals to drive their revenue like they always have).

Thumbs up/ preferred sources were always a thing. this is them just stepping into a new world of sharpening those edges. I do agree with your broader point that we are about to enter deep echo chamber of AI hallucinations being stated as facts.