If the inability to block an ad is the primary determinant of "ruining" the internet you probably need to re-evaluate your sense of entitlement.

I adblock all youtube comment divs. It's quite effective.

Huh? The ad is an image. It can easily be adblocked.

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.