Where I live now has none of those issues. Everything is on time and if it isn't they let me know. Post office is fast and friendly.
The higher ups told me that what the post offices that are "overwhelmed" do will just scan packages as delivered on their truck so their numbers look good and just get them to people whenever. That explained a lot. They're also supposed to ring your doorbell when they drop off a package. They don't. Ever. They told me to report that anytime it happened. They take it seriously. I guess you have to go higher up if you don't get results.
Another thing a lot of folks don't realize is that USPS is often the "last leg" of delivery even if UPS or Fedex is the primary shipper. Or anyone really. The reason for this is that USPS simply goes where other companies won't. Rural areas are the ones primarily affected by this. Not an issue if you live in an area where they are good. If not, good luck.
Maybe Amazon's drone idea isn't that crazy after all...
I wish my post office was fast and friendly. Usually I'm met with people working the front counter/desk who look like they can't remember what a smile is (generally pretty deadpan) and always seem to look like they're having the worst day ever (how some of these people ended up doing a customer service job is sort of a mystery). There's this one lady who works there who just throws packages into this mail cart that's 6-8 feet from her like they're basketballs or frisbees' with little to no concern for the contents (done that two or three times now with my shipments, and did that when I was there yesterday afternoon actually). That, and even though they have five positions at the counter they never seem to have more than two clerks working the counter at any one time (inefficient during high traffic periods, or busier days). Was there yesterday, line of people out the door when I left, but only one clerk working the desk (The one who never looks like she wants to be there.)
I don't think I've ever had someone from USPS ring my doorbell, occasionally someone will knock on the door when dropping something off, but usually my normal USPS delivery driver starts walking away back to his mail car before I can get up from the couch to walk to the door when I'm home. My worst experience with delivery from them so far was most likely when they dropped off three of my packages off at the wrong address on the same day, thankfully the person who owned that property was nice and honest and dropped them off two days later when they noticed them (some computer parts for a PC I was refurbishing at the time a few years back). How they mixed up the addresses is a bit of a mystery, as literally only the first number and the street name were common between the two addresses, if I remember correctly.
UPS is worse, seen them throw packages onto my doorstep from three to four feet away before. They never knock or use the doorbell, it is nice that they use those plastic bags to put around packages if it's raining though (I've come out to a few packages shipped by USPS that were soaked in a rain storm.) But they sometimes leave packages in odd areas. A few times I've gotten delivery notices saying package was left at front door, a couple of those times though I've found them laying in the bed of a pickup truck that was in my yard or driveway (more secure maybe than my front doorstep, but more difficult for me to find as the recipient as well) (what if it had been the truck of a friend or relative that was just visiting though? I might not have gotten it for days.). One time they said they left it at the front door, I checked the front door, the back door, but eventually found it two hours after it had been delivered sitting in front of my garage behind a vehicle that was parked in the driveway (couldn't see it from the front door, had to open the garage door to see it). UPS also seems to have an annoying habit of if it arrives in the destination city early they will let it sit in the warehouse for a day or two just so that they don't beat their own delivery estimates (apparently, as I've seen this happen on multiple shipments of things I've ordered. Sits in the warehouse for two days for no obvious reason, then gets shipped out the day of the estimated delivery.). They normally estimate delivery between 2:30PM and 5:30PM, but I've seen anywhere between 11:30AM and 6:30PM.