I've been twice now in WV, in counties so far away from everything, the only government presence is USPS. The only proof you're in the modern US is USPS (and a bit further a weird, small public library near a weirder Dollar tree).
Some people have trouble getting their retirement money, other are destitute who found a new, non-homeless life (but have trouble with debt collection or just lost their papers), And from what I've understood, USPS has buildings and employees present everywhere and is really trusted in those deep parts, more than anything the government does.
Wouldn't offering basic banking (and maybe limited but free internet access) be a nice addition to help the poorest in the US?
Just an idle thought I had for a while