How important USPS really is:
5 brand new Apple MacBook Pros shipped directly from Apple's factory in China via DHL Express. DHL Express "forwards them" once in the US to USPS for final delivery. When I call DHL to find out what that means they said they "handed them off" to USPS and it is up to USPS to actually deliver them.
DHL has only 1 USPS tracking number, which says the items have been delivered, but I only have 4 MacBook Pros in my possession. Naturally I call DHL to track down the missing laptop. Nope, they only have the 1 USPS tracking number "for the whole group" and basically say it's on me to call USPS and "they can help you out." In reality each of the MacBook Pro boxes has a unique USPS tracking number on it, which I can prove since I have 4 in my possession, yet DHL can't give me the 5th one to actually track it with USPS.
So yeah, allowing the USPS to be defunded/scrutinized/raided/crippled/etc. is stupid and will do nothing but hurt people actually try to live their lives and conduct business while increasing costs for shipping for worse service.