Kant's 1st Imperative -- Back to universalizability: If everybody used Adblock, then many sites would shut down. That's universalizable. In fact, I'm encouraging the universalizing of this one, rather than what you're assuming, which is that I'm hiding within "It's alright if I do it, so long as the bulk of traffic doesn't".

Kant's 2nd Imperative -- Blocking ads is the outcry, then. They have the basis of free rational action to provide an ad, I have the basis of free rational action to decide whether to view it.

Utilitarianism -- Blocking ads downside: Less economic churn (might be positive). Blocking ads upside: Reduces malware vectors, thus decreasing the chance of malware targeting nuclear facilities spreading and leading to nuclear annihilation of the planet. Given the infinite magnitude of harm, even the most improbable odds outweigh. ((Seriously, trying to actually calculate utilitarian probability is a fool's errand.))

Rule Utilitarianism - I reject that your proposed rules lead to the greatest good. Alternate rule: Permitting malware vectors to run is harmful, thus blocking malware vectors is positively ethical.

Social Contract -- Websites provide open streams of information without negotiating terms. This might apply to "Wait X seconds before seeing your content" type ads, I'll concede that.

Virtue Ethics -- You might feel shame for supporting ad-based revenue systems. (Seriously. No shame here. I'll tell you to your face that I block ads. If you proceed to block me, that's entirely fair. At which point I can decide whether I think it's worth viewing ads for one time to see the content.)