There were many lingua francas of which French was supposedly the first global lingua franca. That changed and it became English (from what I understand). We will probably see another language become the lingua franca, so my question is: should it be English? Are there better candidates out there? Why / why not?
This forum bringing together people from different countries, is in itself proof that there is a reason. Many people are already comfortable if not fluid in the language. How many folks speak Esperanto already?
As many as Lithuanians, Latvians, or Basque, and twice as many as Estonians.