I grew up multi lingual before moving to the US and there are still several things that i have to say "well, there's no word for that in English but it's kind of xyz". There are so many ideas, thoughts and feelings that cannot be captured with the English language presently.
Of course every language has that issue across borders so I'm not convinced standardizing in english as a global language will bring enough benefit to be worth the cost
It is also incredibly open to new ideas and words, best put by James Nicoll >The problem with defending the purity of the English language is that English is about as pure as a cribhouse whore. We don't just borrow words; on occasion, English has pursued other languages down alleyways to beat them unconscious and rifle their pockets for new vocabulary.
I do however learn and use the pleasantries of any local language because that's just good manners.