You search for “blah”, Google gives you a bunch of bad results, and serves up 5 ads. Nothing matches what you want, so you search again “blah but not foo” and you get another 5 ads. If search were good you’d only see 5 ads, but because it sucks you get 10 ads.

If Google had real competitors, bad search results might mean people would give up and use a competitor’s search, but because they have a search monopoly, they can enshittify their results and show even more ads without losing users.