Actually European integration the last 30 years has been pretty remarkable. In the past, not even electric plugs were compatible. But the EU is not a country. A lot of the inefficiencies are actually features sought by key members to protect their own local incumbents.
Your best example of European integration is electric plugs?
USB-C!
How about tap water has to be drinkable in every EU country
Many non-eu countries have drinkable tap water, not sure how representative of "integration" this rule is.