Stack Overflow has seen a substantial decline in traffic over the last year that appears to be accelerating. https://observablehq.com/@ayhanfuat/the-fall-of-stack-overflow
There’s no specific AI detection at the moment, as far as I can tell. But it has “listicle” detection. If you ask “best lawn mower”, all these “the 5 best lawn mowers of 2023” websites with affiliated Amazon links get pooled into a compact Listicle section, that you can just scroll past and ignore.