LOL Esperanto is a language that was invented specifically for the purpose of being a universal second language. It has many elements draw from the pre existing languages and is basically built out of cognates so it is fairly easy and quick to learn. SO if everyone was taught in (like everyone in the whole world) as there second language then it wouldn't matter where you went you would never need a translator because you could just speak Esperanto. Plus some things don't translate exactly or thing of huge world meetings where there's like nine different translators trying to play the telephone game with each other. Why can't we all just speak, English, Spanish, French, whatever for your first and then if you came across someone that doesn't you can just start talking in Esperanto.
BUT it never caught on because people were like "That's just english now" but it's not because A English is a ridiculously difficult language to speak properly, and while I don't think it's to much to expect you to learn some basic phrases in a few years, I know being fluent in another languages is another matter. Not to mention our spelling is idiotic at times, where Esperanto is literally designed for simplicity and easy of use. soo yeah PLUS it has that lovely nutraltiy of not being bais towards any one culture, it truly is a language of all the world.