Many of these sites, full of popup ads, have developed their code to overpass ad-blockers.
This is but intention, and it is a continuously fight between ad-blockers and the sire developers. Every time an ad-blocker comes with a solution, the site developers come with a counter-solution.
This is the way those sites make money, and they will keep finding ways to overpass ad-blockers.
It is also a fact that several, if not many, of these popup ads are harmful.
Personally I try to avoid using any site that forces these popups, mainly streaming or download sites. I had my account of infected systems. No more risks to take.
Just thing about it, if they were legal they would not need to use these tricks. If they are illegal, they do not care about having harmful stuff in their pages.
Anyway, it is your device, it is your own decision.