The Original Cookie specification from 1997 was GDPR compliant (2019)
If we'd never had cookies or we ban them now we'd be left with basic auth over https. That's equivalent to a first party cookie. It would be enough to create an ecommerce site with a cart and a recommendation engine. Every single site would have the same login form, managed by the browser. I guess we'd end up with an  or  tag to embed it inside the page and style it.Another consequence, there would be more server to server communications because the first party server could send all sort of information to the servers that are setting third party cookies in pages now. The focus of privacy policies would be there.Probably no way to implement OAuth.