The unbanked are people who have issues to access bank system and can not have their bank account.
what issues are those exactly because they need to work them out so they can actually be a part of society. you cannot be a participating member of society without a bank account that's just the honest truth at least here in the usa. if they have money to buy bitcoin they have money to open a bank account.
It is true in all countries, not only in the USA.
Nowadays, even you are an old person, and you have a small business like a food store, a grocery store, you will have to install and accept many options for payments from your customers, cash most common payment option likely, bank transfer, e-wallet transaction and maybe Bitcoin, cryptocurrency too.
Bitcoin gives us a good option to reduce inconvenience of access to banks but through a long way, people will still have to use banks.