Bad ads aren't just virus or scripts, but also noisy ads, prize game ads, blocking ads(ads that block the whole screen) and such. That's why I mainly use adblock, but, Nexus Mods has no ads like that, just normal ads that don't block the screen or are noisy, so, for Nexus, my AdBlock is disabled. I support AdBlock, but for noisy ads, screen-blocking ads, redirecting ads, video ads that prevent us from accessing the videos we want(happens a lot with me on Youtube). I have a channel on Youtube, and I know the other end of the spectrum.
