SEO wars are at least part of it. Google's algorithm has evolved over time not just top optimize advertising views/clicks and take over more screen space, but a

SEO wars are at least part of it. Google's algorithm has evolved over time not just top optimize advertising views/clicks and take over more screen space, but also to battle the constant gamification of their algorithm by SEO that, once you eventually get to the real results, will surface less relevant/spammy/scammy etc results if Google doesn't constantly push back against the worst SEO abusers.