I just registered an account here specifically because I've noticed it a ton recently and I wanted to reply to this since it's been on my mind. From my experience, google's quality has been going down in general for a while now, but very recently (the last few months or so?) it hasn't been just unusable in a figurative sense, it's been quite completely literally useless to the point of basically being broken.
I really wish I could remember some specific examples of what I was searching for, but I've had more than one experience where it felt like if it couldn't find something on reddit or wikipedia (which I usually have to give it some assistance anyway with the site: filter), it was like that thing just didn't exist. It was just pages and pages of what looked like fake AI generated articles that were only maybe slightly adjacent to the topic I was searching for. If it happens again or I can remember a specific case I might try to update my response.
Disclaimer: I use bing 50% of the time depending on which browser profile I have open. No real specific reason here, just that I didn't bother updating the search engine settings on all profiles. Ironically, bing, which I had always regarded as inferior, does manage to give better results in some cases, but even still I feel like the quality has (somehow?) managed to go down as well.
Lately I've been trying to use mojeek, which (to my understanding) unlike other sites like DDG actually has its own crawler whereas most alternatives are just frontends for google/bing. The results are kind of wonky a lot of the time, but at least it's not so much fake unrelated garbage.
I do have an adblocker on all the time. Perhaps that's related. Maybe I shouldn't be surprised that my experience is so shitty given that I'm clearly not their target audience, if we're just talking about advertising.
Just this morning I noticed that ChatGPT (which I usually hate using) was giving me better results than google. Not just in a little way, the experience was about 100x better. Theory: they're trashing their search engine product to try to force people onto their "AI" products. Probably not that far-fetched. If they really want to push one product over the other you can either make one product a lot better than the other or make the other product a lot worse.