That certainly hasn't been my experience. The USPS is fully unionized and has even less of an incentive to handle with care.
A while back there was a ‘study’ of damage and shippers. UPS was the least worst. Worst worst was USPS.
BTW, they ain’t all union at UPS.
We send out dozens of packages every day, using M-Bags, Media Mail, registered, parcel post, 1st Class and Priority and their service has always been excellent.
In many years, we’ve only lost five packages total.
I don’t understand the hatred found on this site towards the USPS, they’re the foundation of our business, and many other business, and always do exemplar work.