First, I dont think lack of a language's presence online means that the language is dying. For example the world could be becoming more multilingual.

Second, the whole world doesnt need to speak the same language for cohesive unification. We just need star trek level translation which doesnt seem so far fetched these days.

Finally, everything comes and goes- the stars, the tide, human life, and language. Have you tried speaking to someone from east Baltimore lately? I havent either, but according to my source, The Wire, they speak a language that would probably be close to unintelligible between people from other parts of the English speaking world.

In other words, I'm not worried about language diversity- whenever humans find the need to express themselves in ways that doesnt fit in the current framework, they find a way.

I welcome your attempts to learn and speak Mandarin as that single global language.

I wish I could upvote this more than once. A lot of comments here are positive about the idea of a single global language when it's their language that wins out. I strongly suspect that if it were Mandarin, Arabic or Russian instead of English that was being suggested, their enthusiasm for the idea might be more muted.

I understand the sentiment but I disagree.

I think language is a clear representation of culture - your first language directly informs how you see the world.

The world would be a lesser place if everybody grew up with the same linguistic experience.

There will always be regional dialects, accents, terminology, slang etc.

Should we all use the same programming language as well?

I think a more apt analogy wouldn't be the use of the same programming languages (which is more of a private action between the programmer and the computer), but more like using common protocols, APIs, and standards that allow interoperability.