Yes search engines make their money from adverts, but without decent organic listings (where ~90% click volume still goes), there's going to be no one to click

Yes search engines make their money from adverts, but without decent organic listings (where ~90% click volume still goes), there's going to be no one to click to ads. It's a fairly simple mechanic. SEO is likely depreciating gradually as Google gets better at 1) devaluing link spam and 2) accessing and assessing website content for its meaning, but it's unlikely to ever be perfect at doing either.