Personally, I absolutely love if we could have something looser, like a "Common European Area": freedom to travel, freedom to study, freedom to live, freedom to work. That's it. No EC/EP or anything like that.
The idea is that (completely reasonably) if you have a “single market” as you describe, you need harmonised regulation so everybody is on a level playing field; once you have done that then you need some form of democratic governance.
Everyone basically ends up designing the EU when they do this.
I didn't really describe this though. Had I mentioned currencies or trade agreements you might have more of a point.
It's more like automatic work permits for Europeans within Europe, unlimited stays, ease of access to renting + purchasing housing.
It is pretty obvious that the common foreign policy is more important than ever. Sadly it is too late to include Canada, South Korea, Australia and Japan into that umbrella, at least this time around.
And people here in Sweden are talking about that next we will need to give up our currency and use the Euro since that is what T will weaponize next, going after the smaller currencies.