The thing is that according to the Universal Declaration of Human Rights privacy and the right to private communication is a basic human right. And GDPR was literally enacted to enforce this human right.

Now one basic principle of democracy is that supreme courts are superior to the people in power. Someone needs to watch the lawmakers so to say. Because it could actually be that the European commission enacts laws that are illegal. And Chat Control 2.0 could actually be illegal because it violates the Universal Declaration of Human Rights. However, somebody has to take them to The Court of Justice of the European Union to test it.