Wait, weren't dialogues that force you to give consent for non core parts of the experience forbidden under the GDPR? As in, you can't force people to consent by witholding service if they don't?
Ad tech has taken full carte blanche for long enough. If you actually dig into GDPR you find that it's quite reasonable, far better than the cookie law and other earlier iterations that fundamentally misunderstood technology.
The idea that people have to be protected from themselves and their choices is at the heart of GDPR. It prevents people from making the correct choice of not using services you disagree with and keeps those services profiting and ever more centralized.
But digging even deeper, there's this delusion that your usage patterns of someone elses' property are yours and to me it seems crazy. You wouldn't say that physical grocery stores cannot keep track of who enters their premises and what they bought (or how long their phone SSID was in range of $x aisle). Or that they should be fined, and have those fined backed up with government violence, if someone demanded the grocer delete the data.
Yet services like Facebook will have a shadow profile for you from data built up through abusing access to other peoples' systems.