European people also still have a much stronger national identity than a European identity, especially compared to the US with state vs. country level.
The translation infrastructure is huge, and reasonable-quality machine translation⁰ has been freely available for years now.
I don't mean to refute your experience, but I am suprised by the claim, because it's really not what I've seen here. Could you give some more detail on what you mean.
⁰ EU procedure mean there are aome notable absences in the list, but it's pretty comprehensive once you include citizens' second languages. See https://european-union.europa.eu/principles-countries-histor...
All of this is correct, and that's why the single market for goods (except for booze and tobacco) has been such a massive success. However, lots of growth (particularly in the US) comes from services, and for this, languages matter a lot more.
Sure, lots of continental Europeans speak multiple languages, but the vast discrepancies in languages and regulations (insolvency, capital markets etc) means that there are dis-economies of scale in the EU. Like, there's a reason that companies start selling in their home market and then move directly to the US.
A common language can't be assumed across the EU, while other large blocs (China, US) can make this assumption which is important for services trades in particular, as well as bespoke goods trade.
(This despite Ireland and Malta having it as an official language, and the Nordics often having better English skills than natives.)
Come to Ireland, we have Guinness!
There's no reason to expect the warm clothes to be made in the north and the cool clothes to be made in the south.