EU isn't all that great. It could be, but it isn't. Needs major reforms.
Discussion
That said, there are things the EU brought, that really did integrate our countries tighter, which I appreciate. I can't really imagine going back, and don't desire it.
For Romania it is very bad (regarding prices), we were forced by the EU to align prices with EU countries and the Euro, but salaries are still calculated in RON. The discrepancy is very large. Since we are not accepted in the Euro zone (money), there is also a large migration of Romanians to Western countries. It is completely crazy what is happening in Romania.
Anything which centralises power is never going to be a good thing. It doesn't matter how many reforms and tweaks you try to make, it'll always be what it is. The people running the show see you as cattle, little more. All power should be decentralised to the furthest extent possible and to me, as an Englishman, the EU prooves the validity of that point of view.
Subsidiarity?
Yes, but I think the EU actually did that, on a smaller scale, with things like freedom of movement and internal markets. By freeing the individual or business from national burdens or limitations.
I have worked for companies that escaped draconian national regulations by reforming on the EU level or suing in EU courts.
It's complicated.