How common are individual streetside mailboxes elsewhere in the world. That's really the only thing where I could see a real need for specialized vehicles for,

How common are individual streetside mailboxes elsewhere in the world. That's really the only thing where I could see a real need for specialized vehicles for, otherwise for neighborhoods that have on-foot delivery or centralized boxes I totally agree any ordinary delivery van should be just as good for USPS as it is for UPS, FedEx, Amazon, etc.