The United States works because it has one currency and member states are not sovereign.
The EU will fail because it tries to impose law on sovereign states. Eventually, there will be a breaking point. Either the member states will give up sovereignty or the union will fracture. The only question is how violent will the fracture be?
Maybe some member states stay together and call themselves the EU but it’ll be a shell, a ghost of what once was.
Well our federal government has taken control over what our constitution delegated as power to the states. Most EU members use the euro.