[NateEag]

Conceptually, there is no way to make trusting cookies both simple and transparent.

Even something as simple as a unique identifier can be used for both helpful and malicious ends. You'd need to read all the code pertaining to it to have a clue if it's something you should accept, and you can't ever know what the server's backend code is, even if it claims to be open source (it can always be running extra components that are not developed in the open).

So, opt-outs are inherently a flawed idea, at least with any granularity.

Turning off cookies entirely in your browser then opting all-in for sites you choose to trust is about all you can reasonably do.