Honest question: what you’ve described is very disturbing (having to wade through lots of bot reposts), but why would this be Google’s fault (or DuckDuckGo’s or Bing’s or StartPage"s or Kagi’s)?
I’m not trying to save the search engines since they’re also out to make a profit, but if half the internet is spam, why would this be a search engine’s fault? I mean, we can complain it’s not sophisticated enough to navigate through the crap