Getting off the peso means a huge loan to buy all the existing money to get it on USD. It'll be real interesting to see if it can happen. Argentina has and can be great. I wish them luck.
I doubt they can come up with enough dollars in one shot to switch over all at once so that's unlikely.
It looks like the list of countries besides US that exclusively use USD is small, none with a population over 100k, although I know several economies have de facto dollarized: https://en.wikipedia.org/wiki/Currency_substitution#Countrie...
Maybe that Wikipedia list is out of date. I'd thought Ecuador was running on dollars.