Earlier quoted context omitted.
https://globalprivacycontrol.org/ goes kind of in that direction. It's a rebranded Do Not Track header, but referencing specific privacy rights under GDPR/CCPA. That hopefully makes it enforceable, whereas advertisers could just ignore Do Not Track.
I like the idea, but that protocol is too simple. For example, I don't have too much of a problem with Matomo tracking cookies, but I don't want Google Analytics to follow me around the web. This header doesn't specify any of that, and I'd still need to give some kind of consent through a cookie pop-up to websites that want me to use that stuff. I'd rather see a modern version of P3P ( https://en.wikipedia.org/wiki/P…
I think DNT/GPC can be more fine-grained than you make it out to be. The spec is simple, but there's nothing in there that stops you from developing a browser extension that only sends DNT/GPC signals to a curated list of known bad trackers. That would give you as an advanced user some configurability while it's a simple checkbox for most folks.