Economic status of EU:
I think one of the main considerations is the sheer size and wealth of the consumer market in Europe. We are accustomed to think of GDP rankings in terms of individual countries. When we do so, the U.S. is number 1, followed by China and then Japan. However, if we look at Europe as one entity, then it is the largest. Since the EU does make Europe ONE economic entity so looking at Europe this way in not unnatural.
If we look at this way, Europe is tops with a GDP of 16 trillion (roughly 26% of world GDP), followed by the U.S. with 14.6 trillion, China with 5.9 trillion and Japan with 5.4 trillion. Germany follows with 3.3 trillion.
Look at the following link and you will see what I mean. The rankings are by nominal GDP
https://en.wikipedia.org/wiki/List_of_countries_by_GDP_%28nominal%29
In terms of population, the EU has over 500 million consumers versus 310 million in the U.S. These are generally consumers with a much higher GDP per capita than in China or India, making the European consumer highly desirable.