I'm not sure if you've ever had to learn English as a non-native English speaker, but it's one of the hardest, most painful, longest things to get truly proficient at, equal to other very hard aspects in one's very hard profession.

There are hundreds of millions of smart people who can't communicate their ideas to us in even simple English sentences. Whereas English grammar, as long as you avoid idioms, is pretty accessible as far as natural languages go.

So to sum up: as a global language English is maybe okay, but its writing system makes it not at all okay.