"For 100 years or so the only people creating currencies that are adopted on a wide scale are governments (or the private banks they employ)."

May I suggest that you have the power relationship backwards here?

"My key point here is that PEOPLE ACCEPTING IT AS VALUE IS WHAT GIVES IT VALUE!"

This was only true when the dollar was backed by gold. What gives value to the petro dollar now is the American war machine.

And even before 1971, what gave monopoly power to the dollar over other perhaps more efficient/convenient currencies was the forced by threat of violence insistence by government that taxes be paid in dollars.