All may be true in some states, but this has nothing to do unfortunately with the topic at hand as detailed in the OP. Every Post Office in this nation has an actual valid street address, so that's nothing new.
Try opening an account at a bank with just P.O. Box # or USPS street address and see how far you get these days.
If you are successful, it's only due to the fact that the bank employee who opened the account somehow skirted or ignored the laws governing requiring a legitimate street address, or wasn't aware of the requirement as is lawfully written.