Ostler overestimates the power of technology when harnessed to the stupidity of average users. What happens in actual practice when a computer hears an odd dialect, barely understandable in the next county, or reads a poorly spelled text?
Errr, does not compute! Buzz, pop! Fizzle...
As for English, it fits the profile of
lingua franca and continues to have a certain cachet & practicality for conducting the world's business. Among languages in the Roman alphabet, it is relatively free of diacritical marks. However it suffers from a surfeit of homonyms that can confuse even native speakers. It seems to have been common practice to use the language of the hegemon in decline, not its successor.
Actually even native speakers may need to become fluent in the pidgin versions spoken by non-natives, i.e.
Engrish!