I assume you've considered this, but what about deprioritizing precisely what spam sites use to SEO, or concocting some other identification algorithm, to filter precisely those out?
While yeah, marginalia finds interesting stuff, I've not been able to find anything useful that I've tried searching for with it so far.
The problem is the system. You can expect one or two persons to act rational, but at the scale of 100s, 1000s, millions, it's just crowd dynamics following statistical processes, just as the market itself is.
If we want anything to change, we need systemic changes to what behavior is incentivized by the world we live in - and I can not think of anything that would do the job other than abolishing or at least heavily restraining capitalism.