The post office is brutally slow!! I've limited my interactions to submitting paper based tax returns when I've done amendments.

The post office is chronically underfunded as a result of hostile federal regulation (mostly put in place by people who want to privatize it and prevent rural customers from getting the low-cost service mandated by law).

So yeah, the post office is a great example: Of what happens when critical services are underfunded.

The post office is also not a traditional federal agency - a directly state-operated power company would have a very different administrative and funding structure.