what do you mean by "legitimate content"? Something that someone posted out of pure altruism and with no intent to make a profit? We can argue about how big of a percentage of the internet that is
I understand, but when you say "ruining the internet", I would prefer deceptive ads that blend in than those that make my eyes bleed, which is often the case with banner ads.
Patio11's ad is an image, and would be blocked. But you're still right, in that the closer one gets to mimicking unpaid content (such as Google or Reddit's sponsored ads, which are text) the harder it is to programatically block.