When UPS went out on strike in 1997, the USPS had an avalanche of mail for a period of months. If UPS or FedEx go out on strike or stop business for any reason, without a federal mail service, things will grind to a halt.
Deliving mail is not rocket science, any more than fast food or convenience stores, and entrepreneurs both established (bus companies, trains, airlines, etc.) and new would move in quickly. Heck, I'd do it if no else wanted to (at least across town). Wouldn't you?
Good point.
Shutdown the USPS and fire ALL the worthless slugs that work there.
Then fully privatize the functions the USPS used to purport to accomplish, and make it federal law that they can NOT be unionized (read that, taken over by union thugs).
DONE.