Google search has been pretty weak for awhile now. I/O spoke a lot of big talk about bring generative AI into search, but from my part of the world it still seems the same.
I think it's both - the SEO fight as well as the explosion of ads on Page 1. Throw in a dash of average-user search optimization (vs a flatter term-based search) and you've got Googles downfall in a nutshell.