Most of them are unbanked basically because of lack of education. They are mostly uneducated in the rural areas and this explains why they are mostly unbanked. And also, because if lack of trust for the system.
I am sure the same issue affect BTC, most people lack the right education about BTC.
Yes, you are on point, and I agree with you on this very statement of yours, because truly the unavailable of banks and internet network in most of these places have a big role to playing why there are a lot of unbanked people, which I have strong doubt it's a menance Bitcoin can't remedy, as to be able to own Bitcoin, one need a bank account where to deposit fiat which will be used in buying Bitcoin via p2p or any other means.
Yeah. We can't trade BTC without having a bank account. If you don't have a bank account, how do you convert your crypto currency to Fiat, except until BTC or crypto currency in general becomes accepted as a legal tender.