I kind of agree with you, and (as a hobbyist linguist) I believe a diversity of languages is a beautiful thing, but it creates unnecessary friction for business and about everything. Europe really needs a unified language -- it could be English, French, German, or even Interlingua or Esperanto.
Lingua franca really matters. China, for example, didn't have a unified spoken language until about 100 years ago. However, Mandarin is today universally understood and spoken in the country. And the result? You only to know one language, and you can have access to one of the largest markets in the world. Alas, the same could not be said for Europe.
(In fact, Europe needs a unified language if people are serious about getting rid of English and the Anglo-American hegemony, because each smaller language really cannot fight English now.)
I think that's the point of this article to be honest.
If we lived in a fair and just world, the EU having the 4th largest economy doesn't seem like a bad thing. Going by numbers alone China (1.8bn) and India (1.5bn) are much more populace than the EU (450mln).
However, I would would probably side with the author and personally much prefer a group of liberal democracies following the rule of law to always be on top. If the world needs to bow to autocracies then we will have a bad time, Russia is just the prelude.
