It's the task of parliaments, governments, and courts to reevaluate and resolve all these contradictions over and over again. It's tedious and takes a lot of resources, but that's the price for democracy.

The constitution of the Democratic People's Republic of Korea (i.e. North Korea) famously guarantees freedom of expression as a fundamental right for the people. That hasn't stopped the government from trampling all over freedom of expression, though. The EU is of course nowhere near North Korea in terms of what is considered acceptable, but don't ever trust that the words in the constitution will be enough to keep the government from doing something.