Earlier quoted context omitted.
It's weird to me to hear comments like this. To me the postal service just seems like a slow email service with no spam filtering. (Sure they can delivery packages, but they're not unique in that regard). I get the utility of certified mail and associated services, but I don't really understand why we need first-class/marketing mail service in the 21st century. I agree it was important infrastructure 250 years ago.
Because not everyone can afford internet access?
And those without internet access can go to public libraries or even get free public wifi in many cities. Even some homeless shelters provide wifi now, which is much easier for them than providing mail service. Technically, I think those without a permanent address can register to still receive mail at a post office, but that seems more difficult to manage and more limiting than finding internet access.