Every letter still requires paid postage. The problem is, if you set the cost to be actual cost incurred, then anywhere remote or rural will be ridiculously expensive, and no one will send stuff, making the packages/letters that do need to be sent even more expensive, and creating a death spiral. It's no different than a million other public services that we pay for despite not using (public rec centers are sponsored in part by taxes despite charging admission/membership fees, daycare facilities get partially paid by the government, universities get some tax money despite the crazy fees we pay, etc).

But regarding the pension, I disagree - I believe that every job should be sufficient for someone to live comfortably on - why do we have jobs if someone can't live on them? And the reason they pay well and have pensions is because they're unionized, aznd have fought for the pay and pension they have.