My replant to Stan Corbett on the matter.
Stan,
I feel mailing letters is not going to keep posties in a job. No more than going to a personed check out out is going to keep the checkout person in a job. Try and find a service station that fills up your fuel tank.
With technology advances in self-driving vehicles and robots, its quite likely that at some stage in the future the postie will be completely replaced by a machine. You could then argue that you are keeping the people that make the machines in a job. But what happens if the machines are made and maintained by other machines which are inturned by other machines, and so on?
The luddite movement has almost completely disappeared.
Personally I'd rather save non-renewable physical resources than save a persons job
As a very good friend of mine says, we need a fundamental change in the way society operates.