Why doesn’t everyone speak English?
Well, millions are born in countries where English is not the local language.
Russian kids speak Russian, Japanese kids speak Japanese, French kids speak French. I know that millions of people want to speak English and spend a lot of money learning it. It is very hard to learn it as a second language.
BUT it is a beautiful language with many shades of meaning to better describe what you want to say. In a little dictionary and thesaurus I have the word nice has 23 other words to describe something that is nice. (i.e. attractive, likeable, pleasant and many others).
I think English is the only language with a thesaurus.