They never should have made opt-in an option in the first place. All the legitimate reasons to store data are already permitted without asking permission (required for the site to function, or storing data the user specifically asked the site to store such as settings). All that’s left is things no one would reasonably choose to consent to if they fully understood the question, so that should have just legislated that the answer is always “no”. That plus a bit more skepticism about what sites really “need” to perform their function properly. (As that function is understood by the user—advertising is not a primary function of most sites, or desired by their users, so “needed for advertising to work” does not make a cookie “functional” in nature. Likewise for “we need this ad revenue to offer the site for free”; you could use that line to justify any kind of monetization of private user data.)