Auxiliary languages are kind of inherently doomed to fail to function as they're intended because in order for them to function as such, commitment needs to be made to adopt it multilaterally by governments with sufficient influence. If today the United States and China bilaterally decided to force Esperanto into their school curriculum it'd likely be adopted very quickly by everyone else, but that isn't the case and I doubt it ever would be under almost any circumstance, because learning English is just immediately more practical, even if it's a significantly more difficult language to be picked up.

And that's how it's played out. Nearly every developed nation teaches English as a second language or is a native population of English speakers. The universal language is English. The JVM bytecode for people is English.