Think about it like walking into a store, but before you enter you have to agree to the tos and sign. You see how bad that would be to the user experience. Today I believe the store can track you as much as they want to. There is no opt out.

The thing is, too, that remembering your decision to reject all has to be done through a cookie, and they know this and take advantage of that fact! 99.9% of websites only offer a choice that makes you dig through at least one menu, or a choice that makes you have to click the 'reject all' button every time the page reloads.

There needs to be a mandate to add an option to "reject all except my decision to reject" that corresponds to a single boolean. It should exist under a standardized id, and if it's set to true, the site would be required to stop showing you cookie popups. And if the cookie contains anything more than that single boolean and the website it applies to at most, it should be illegal and reportable as such.

Of course, as you mentioned, that would probably be quite difficult to accomplish legally.