I guess you missed the part about "clearly marked with the word Fragile" such word that YOU said they don't look for....
Spend a day at the post office and UPS, you will realize the people handling the package will see the fragile markings. But once it gets on the on a conveyor and the barcode reader sees it, all that is seen is the barcode. The machines don't read, if you want personal hand to hand service, it is available, it is called Registered Mail. But even then sometimes the machines reads and moves the package.
It still boils down to who packed it and if they know how to pack it properly.
Whatever makes you think I have never seen how packages are handled at the post office?
With very few exceptions, like airplane crashes and highways collapsing under trucks, if UPS or USPS or FedEx always do their job properly and never mishandle a package, every package would arrive at the receiver's door in exactly the same shape it left the senders. Period.
If a package falls off a conveyor, that is the carrier's fault - not the sender's. If a package marked "fragile" is sent through a conveyor that is the carrier's fault not the sender's. If a package gets dropped on the floor and run over by a forklift in the sort facility that is the carrier's fault not the senders.
I am a small business but I have been shipping about 1200 packages a year since 2003. In that time I can count on one hand the number of packages where the contents were damaged but have had hundreds of reports where the package was damaged. and a couple where it was not delivered. I had one mailed to NYC and delivered to someone in Portland Oregon. I also self insure so if the goods I send are damaged in transit it is my loss. Quite frankly I take umbrage at the suggestion that I don't know how to pack the items I ship.
BTW I'd be interested in knowing how many packages a year you ship? You said you receive a lot but didn't mention how many you send.