It seems our mail carrier experiences are quite different.
This is as YMMV a topic as there can be, with so many variables, local and regional, if not national, that will affect the experience, often only heard about if negative.
For the most part, the carriers that serve my area do a good job. I do get the occasional mis-delivery, and in the past have had magazine issues go missing (though the bills arrive 99% of the time), but on my route, the USPS consistently delivers the mail no later than the late PM, even with the temp fill-ins who have taken over the route from the retired long-time carrier.
Sunday Amazon deliveries have been made by both its own drivers, and on occasion USPS drivers.
Similarly, Amazon's tracking of its own carriers is very good, down to the number of stops away their driver is, though there is less intermediate detail than there used to be. But that could reflect the expanded nature of their internal logistics. Understandably, when they contract with the USPS, they have to rely on its tracking system, and don't have direct control over what the latter does, or information it conveys.
One tracking system that has turned noticeably for the for the worse is UPS', which lacks the detail it used to in the past, at least for a non-paying, non-registered user, and now carries a disclaimer that WYSIWYG, even for their own agents. If that's the case, then it's a downgrade for everyone.
The UPS tracking numbers for their Amazon return service lost any meaning a while ago, other than as a dropoff record, which is understandable since they're consolidated shipments, rather than individually shipped and tracked. But it's no big deal since Amazon often issues credits as soon as the chain of custody is in their hands.
FedEx is pretty good, though it helps to keep expectations in check for service from their Ground (nee RPS) division.
Such complaints will get no sympathy from those who have bought from Aliexpress, or other overseas sources. The variables and uncertainties in those shipments only compounded by the fact that the USPS, or another obscure local last-mile carrier is one of the parties involved. Those shipments arrive when they arrive, and patience is mandatory.