Honestly the biggest failing is just SEO spam sites got too good at defeating the algorithm. The amount of bloody listicles or quora nonsense or backlink farming websties that come up in search is crazy.

This is bullshit the search engines want you to believe. It's trivial to detect sites that "defeat" the algorithm; you simply detect their incentives (ads/affiliate links) instead.

Problem is that no mainstream search engine will do it because they happen to also be in the ad business and wouldn't want to reduce their own revenue stream.