It really doesn't matter which language it is, as long as it's not super hard to learn. The hard reality is, if you have N languages and speakers, to communica

It really doesn't matter which language it is, as long as it's not super hard to learn. The hard reality is, if you have N languages and speakers, to communicate without coordination either they have to each learn N-1 other languages or just 1 with O(1) coordination. The rest just happens naturally via network effects.