I have a really hard time understanding what lasting effect El Salvador hopes to accomplish.
> More than half its citizens rely exclusively on cash rather than credit or debit cards
That's not in itself a problem.
> Some 70 percent of households have no bank account
That's may be a problem, but is it something that Bitcoin itself can solve? For example, people who have no savings and survive hand-to-mouth really don't need a bank account. Maybe that's what the 70% statistic is telling us.
> and nearly 90 percent do not use mobile banking.
The experience of using bitcoin for most people is not unlike the experience of using a mobile banking app. What is it about Bitcoin in particular that makes it a better fit?
> A digital payment platform could be a way to make the economy more inclusive and accessible.
Possibly, but only if the reasons for lack of inclusivity and accessibility are understood, and Bitcoin is compatible with resolving them. If the reasons are social/political, Bitcoin is not going to help at all. Monetary policy is effectively set elsewhere, either Washington or the Internet through the Bitcoin protocol. Being the hardest form of money ever created, bitcoin is especially bad at funding public works projects like the kind El Salvador is going to need to elevate its standard of living.
Then there's the elephant in the room: money printing. El Salvador has no currency of its own. It uses the US dollar, and now Bitcoin. This means that the government has voluntarily foregone the ability to print the money to cover the debts incurred for domestic spending. Adding Bitcoin just doubles down on the status quo: no domestic currency and no possibility of money printing.