English is pretty good, I agree, though phrasal verbs are the work of the devil. It has a head start in aviation, mathematics, engineering, some television, finance, and computer science. The British did a good job of seeding it everywhere and WWII gave it a large boost. Then again, the dissolution of the empires in the 60s made English and French less fashionable in many areas of the world as nationalism took hold.
Favoring "gradual unforced adoption" is a fine thing. I suppose I favor it too, as a "lingua franca" but not as a single global language. Knowledge of history does, I'm sorry to disagree with you here, qualify one to have a credentialed opinion. Language hegemony has never happened without a lot of people getting killed. I do not favor that, and I trust you don't either. Maybe this time will be different, who knows? America has always had wonderful, astonishing optimism.
But keep in mind that what you are proposing is no less than closing the book on many venerable, vibrant, and (ahem) more populous cultures. They will push back as much as you would push back on being told that English was obsolete.