Some things require scale. As I say elsewhere in the thread, UK left for this very reason and is worse off in every single metric they were hoping to improve - GDP growth, immigration control, quality of governance, environmental concerns, amount of red tape...
The workings of a bureaucracy are not the same as the final outputs. IMO and IME the quality of EU outputs is generally high.
on the macro level though I can't see it myself.
EU area had everything going for it in terms of being able to make drastic progressive shifts forward in multiple areas. but instead since 2008 its been doing little but dealing with the contradictions of its own self-imposed constraints. be that debt crisis, energy policy, fortress border policy, emigration issues, Brexit and endless political dramas over reactionary political movements. It's now fixated with re-armament, something that threatens to produce yet another lost decade.
Meanwhile, China and other parts of Asia have taken these same 20 years to create entire new sectors and lead the world in them.
The rearmament might actually inject a good chunk of investment - let's see.
The Eurozone included economies as diverse as Greece, Spain, Lithuania and Germany
These are some of the self-contradictions I'm referring to.
And the basic issue is that you cannot have a single monetary policy and impose half a fiscal policy, without political unification. And IMO that will never be squared.
I suppose the new glaring contradiction is that environmental policy and net zero policy has primacy (rightly in my view), but now so does making bombs.