It's really amazing how many people relish the thought of ad blocking killing the internet we know today. That there's no viable replacement doesn't matter: I don't think these people have seriously thought about what happens after they win. They're following the ancestral urge to to tear down, to wreck, to fight the system, to start over --- no matter the consequences. It's always dangerous to give power to people who advocate destruction of the supposedly evil old ways without proposing viable new ways.
It's not just adblock that's the threat: overzealous bans against tracking cookies have the potential to do much the same thing. Either way, ad revenue collapses, sites either die or switch to paywalls, and the internet becomes a much smaller, higher-friction, and lower-utility place. It'll be sad.
In a decade or two, the same people who today decry ads and tracking today will be the ones who pine for the open internet of their youth.