None of this works unless the world already runs on crypto. And not even El Salvador actually does that, because the populace hate the bitcoin system, the official payment network is completely unreliable, and the unofficial wallets don't have the fees subsidised.
The most common issue with "banking the unbanked" is a lack of sufficient documentation. This is not a problem in El Salvador, because they have a national ID card, and you can get a basic bank account with that.
And yet, only 30% in El Salvador have a bank account. What does crypto do about that? What need does crypto fill that the existing basic accounts are failing to?
I wrote a book chapter about this crypto marketing buzzphrase. It's been a common buzzphrase in bitcoin and other cryptos since 2013 - and zero of these people have ever given a joined-up account of how this is supposed to work in practice. Not even Facebook, when they put banking the unbanked as a key advantage of their proposed Libra cryptocurrency. https://davidgerard.co.uk/blockchain/2021/02/12/libra-shrugg...
"Banking the unbanked" is a complex problem, and crypto addresses none of the hard bits.