Re: Realism please
I for one can't see how the distinction between such cookies and all others could possibly be made by a web browser or client side app as it can have no insight into the provider's service architecture or corporate purposes.
This is not the point. It's not for the browser to work out whether a cookie is required, it is a legal requirement (under GDPR) that a web site not track users without their consent. Of course, this is a paper tiger if the web site operator is outside the reach of the EU* (although breaching parties could find themselves in trouble if visiting the EU, or if they have business interests there). However, it does mean that trying to track users in this way, without their consent, within the purview of the member states can be a very costly mistake.
*and UK, kind of, as long as we want to keep our data-equivalency with the EU, which our current government seems keen on throwing away.