I'm horrified whenever I see people having this perception of the issue, and worried that it'll get accepted by the legal system as the correct view.
From my POV, the only contract that exists between me and a random ad-loaded website is the one negotiated between my computer and their server - that is, the HTTP protocol, which clearly stipulates that I can render any reply you send me in whatever way I like. This contract provides many tools for expressing the intent of gating content behind some requirements (like payment, or receiving different content first), but the common rule is: you don't send the content you're gating before the client proves they've met the requirements.
And honestly, I'd consider mixing ads into content to be borderline CFAA (the ads themselves being abusive and often fraudlent, and sometimes malware) - and sending software intending to compromise my user agent (like trackers, or ad-blocking busters) to be crossing the CFAA line. Unfortunately, I don't think the lawyers would agree with me :(.