What a sad world where we all have the same culture and language. There's many concepts that don't translate from one language to the next, they form a way of looking at the world. What about foods, and stories and music, nah, sounds terrible.

I also want one big world for all but definitely not a single culture or language

So there's only one single culture in all english speaking countries? A unified language does not in any way imply a boring or "assimilated" culture. Dutch people can still ask their closest friend to Venmo them 2 bucks for the fries they took earlier, germans can still make and drink objectively better beer, and the french can still be black and white and smoking a cigarette. But just in english instead.