2 remarks:

- of course Europe's largest economies are going to be the least incentivized to adopt English due to their larger internal market both in terms of culture as well as economics.

- The International Englishes (plural) are different from both UK and US English. The scientific community has its own 'dialect', and the EU political/administration/diplomatic English is different still. Standard tests based on US/UK spelling/grammar/vocabulary might not capture these nuances.