Postal banking is a thing in many countries. Canada Post did banking from its inception until 1968. The major benefits are that there is a post office in every community, even really tiny ones, and that a Canada Post bank system can offer basic banking services to people who otherwise wouldn't be able to.
This is an advocacy piece, but it includes the history of postal banking in Canada: https://lindsayadvocate.ca/corporate-pressure-ended-postal-banking-in-1968-its-time-to-bring-it-back/
What about the unlabelled grey "dread zone" between the pacific and midwest areas? That's accurate, right?