The USA came together in 1789 as former British colonies with a common legal system, culture and language.
THE EU/EEC started in 1957 as group of nations with a diverse range of languages and cultures.
There has been a co-operative international system including bodies such as the IMF, OECD, WTO which allowed the USA to prosper by co-operatively trading and investing around the World. It was not the USA versus the World - until Trump came along.
The UK joined the EEC in 1973. Until it left in 2016 its GDP per person in USD terms increased by a factor of 13. Since it left the EU (2016-19) ts USD GDP per person has fallen.
Between 1973-2016 The USA GDP per person in USD terms only increased by a factor of 10.7.
Please explain why you think the EU is failing in comparison to the USA.
Figures from
https://countryeconomy.com