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?

Money transfers between bank accounts for no extra fees (well, that's limited to the Euro, so a couple of countries chose to stay outside). Mobile phone usage for no extra fees all over EU (some limitations, but typically not relevant for the average trip).

B2B the integration has even bigger impact.

I don't think eletric plugs are even regulated. British plugs never changed and they were not an argument in Brexit.

Which is why bank to bank transfers are so easy in the US.

Free cellphone roaming is a big plus.

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.

And many non eu don't have. I am neutral on the eu topic but you are confused. If this eu thing can mandate certain water standards or expel a country and or withhold common funds, that's a very different thing from seeing "some" non eu countries having water.

USB-C!

It isn't bureaucracy that has prevented any alternatives emerging; it's network effects. Mastercard and Visa have a solid duopoly.