Consent for the publisher to "access their browser"? Hmm. The Web is a pull-based, client/server, request/response model, not a push model. So it seems odd to me to talk about a publisher needing consent to "access" the user's browser. It is the user's browser (user agent) that made the HTTP request to the publisher's web server. Doesn't the publisher have the right, then, to send a response containing whatever content they wish, since the user requested the content? If the client wishes to filter/block/exclude some of that content, it seems like they have that right, but it seems the responsibility for that is on the client side, not the server side.

Not that I like ads, but I wonder how much of these new policies are based on a misunderstanding of how web technologies actually work....

Maybe the distinction is that the publisher of whom you requested content may dynamically load content (ads) from 3rd parties that the user did not specifically request content from? That too is just how the web works, and it is the publisher who controls what other content to load from other domains/sources. But it still may be a worthwhile distinction...?