I remember in the early days of the internet Alta Vista search worked quite well. It was easy to find what you wanted, and find new things relevant to your interests - and so it became very popular. Unfortunately, Alta Vista only worked well if people made their websites in good faith. It was searching meta-tags and text on the page; and so when greedy people wanted to get more traffic on their website, they found it easy to exploit Alta Vista's search. As more and more people started exploiting the system, the search got worse and worse.

I remember the day I switched to using Google. I was searching for some C programming stuff on Alta Vista with technical words - and the results had more porn sites than programming sites. Like, wtf. Obviously that search doesn't work anymore. It stopped working because arseholes were exploiting it.

And now, pretty much the same thing is happening to Google. Their algorithm worked better for longer than what Alta Vista was doing, but it seems that self-interested people have kind of cracked the system, and now the results are mostly just junk instead of useful stuff. (Note, I stopped using Google several years ago. I've been using Duck Duck Go. But you're right that the problem is more widespread than just Google.)