As someone who makes a hobby of learning languages, I am of the highly unpopular opinion that the world would be a better place if we could pick one easy-to-learn language (e.g. Malay) and one super-simple writing system (e.g. South Korean Hangul) and get our species out of the dark ages of having thousands of mutually unintelligible languages. No-one in their right mind would create an ethical, functioning modern so…
I read your comment and compare to programming languages. It would be revolutionary to have all computers programmed in the same language, but as different languages are good at different things and evolve concurrently, it's almost inconcievable to make it happen. And you're talking about refactoring not merely an entire industry, but the very language of thought for our species! How can we even begin to approach thi…
Human languages are much more generalized.
Sure, you can find domain-specific examples of one human language being preferable to another though, like when Korean Air forced all its pilots to communicate in English, even Korean->Korean pilots, because in English you can tell explicitly a person who is older/more senior than you that they're about to kill everybody on the plane, without defaulting to making that a polite "it seems as though perhaps what if" suggestion.
On a country-level, we've successfully normalized a given language across large populations and large geographies. Often without involving genocide or prison camps.
If we can roll out vaccines to the globe over a couple years and a few trillion dollars, then surely rolling out a global language over a generation or two would only be 1 or 2 orders of magnitude more challenging, but it would likely result in far more benefit to the human race in the medium/long term, and probably even in the short term too.