THe important word here is countries. Since they are ruled by governments and those governments are in debt, unable to function without printing more and more fiat money, they will never be able to or even willing to switch to a decentralized cryptocurrency or even a currency backed by gold or anything else. What Maduro is trying to dois his swan song. People may embrace it but governments won't. Even if 60% of people in a country wanted Bitcoin to become their national currency, the government wouldn't agree because it would mean paying debts that can't be paid, getting real money out of nothing.