I think search results have become worse over time for three main reasons, firstly the amount of absolute drivel that's published on the web, made doubly worse with AI written drivel. It's honestly shocking. Secondly, the web has become more centralised and people use aggregators more than individual sites or services (facebook, reddit, etc.). Thirdly, the internet has become 'safer' in a lot of ways and seemingly the search engines scrub what is probably the majority of results from ever being returned. It used to be quite easy to find a pdf of a book on some open web server from a google search alone, now it's nearly impossible. And I don't think that's because people's security hygiene has improved.