This is the way of the world in microcosm. When globalization has smeared all cultures together, and the only languages left are English, Spanish, and Mandarin, the world will be far more interoperable - but at the cost of every other independent niche society. I’m not actually saying it’s not worth it.
The idea that English (in this case Spanish and Mandarin as well) will kill all other languages is debious and forget a very important fact: through most of history and in a lot of places bilingualism is the norm. Current examples are some African countries where languages local are spoken and French is used as vehicular language; Standard Chinese while people speak another Sinitic language. What is likely to happen is more people being proficient in a second or even third languages (like it is in Hong Kong).
