I mean, yeah I have literally modeled that out. It's not hard at all.

Basically a federated model of both communities and bank to vendor ecospheres.

Community goes:

Individual->local shops

Local shops-> regional shops

Regional-> State

State-> Country

Bank federated model:

Individual-> local bank

Local Bank-> local shops & regional banks

Regional banks-> regional shops & state banks

In this model likely people would run custodial bank lightning software your "Bank account" is just your receiving channel (direct deposit paycheck) and a spending channel (likely equal to your paycheck as collateral)

The community solution is more sovereign bit most people don't care about sovereignty.

So, that's how it scales globally. (Sorry if this isn't detailed enough, I just don't want to retype an idea I have shared many times)