Comment by piva00

Which has slowly been happening the whole time the EU existed, no?

The difference between a single market like the USA, and the EU has much more to do with cultural and language barriers, at the same time different countries in the EU have found their niche in the common market, different countries have their own comparative advantages, and use that to supply other EU members much more easily than pre-EU.

Can you expand on the argument that the EU has failed as a single market? Quite curious to hear that perspective.