Where have you read that this is about checking everyone’s ID?
They are specifically building an anonymous system for verifying age required to buy to products and access media that we already check ID for (not anonymously, but distributed) in physical stores.
Most countries don’t have age gates for accessing social media and, under the EU system proposed for the EU, if they did, this system is exactly providing a method of verifying a user’s age without knowing who the user is. So it’s literally the opposite of what you claim it to be.