I'm not sure I could define it as intentional and nefarious but I definitely find Google search results to be markedly worse over the last few years. It used to be really competent at finding specialist/technical results but lately it's gotten more generic and less useful. It's possible that's actually the nature of content creation these days, with everyone hyper optimising to please the Google search algorithm. But it's resulting in a less useful web for me. Certainly a less interesting one.

Same thing with Youtube, the algorithms seem to optimize for the lowest common denominator and all the interesting niche stuff is lost in thr noise.

Some of the solution is to do a better job of actively searching for good content instead of waiting for the algorithms to recommend it. But that itself has gotten harder too. Finding good content curators is hard.