It is really easy to bypass any kind of adblock filtering by just hosting your ads locally on your own domain, but for some reason all the 'content creators' are to lazy to go back to the old ways. When you buy a newspaper, you can't magically cut images out of it, especially if layout changes from time to time and same can be applied to web pages.
Blame those hassle-free, privacy violating personalized ad networks that infected everything.