Here in NYC Amazon delivery has gone from being amazing and magical to nearly worthless seemingly overnight with this change. UPS (and Fedex) didn't seem to have any trouble delivering even to challenging buildings without doormen, giving accurate tracking etc. Now every time I see USPS as the option I cringe knowing the package won't be delivered, there won't be a door tag left, and at some random arbitrary time the status will change to "attempted delivery" even if someone was sitting on the front porch waiting for it the entire time.
It's getting really bad, we'll see how long it takes Amazon to figure it out.
Amazon at least mitigates this loss risk by unquestionably resending the package without additional charge. This exercise has grown tiresome.
UPS also does a great job. I don't know how they break into my building, but they do. Once in a while the normal delivery person takes the day off, and you get the door tag. Fill out the form online and the package appears tomorrow. Not perfect but reasonable.
FedEx is awful. FedEx means I'm not going to get the package unless I happen to be at home and they happen to actually ring my doorbell.
DHL is also awful (the delivery mechanism of choice from amazon.co.jp to the US). I order a $10 magazine and they won't just leave the package at the door. In fact, they call me to see if I'm at home, say things like "oh, you didn't answer before, I'm not on the way there anymore so I can't deliver it" and other such bullshit.
Finally there are the taskrabbit-like shipping services, A-1, Lasership, etc. If you see one of those you aren't going to get your package. Just re-order it and hope you don't lose the lottery again. They can't even successfully deliver to commercial addresses with dedicated courier receiving and fully-staffed mail rooms.
It's interesting that Amazon finds this to be cheaper than shipping it properly to begin with. Although it makes sense if packages sent through USPS are low-value and not just small.
I'm losing faith in those 2-day guarantees, and the number of items available for Prime has been slowly dwindling. That, and their minimum spend for certain items went from $25 to $35. Starting to wonder whether renewing my Prime membership is actually a good idea.
USPS -> Australia Post means that I can get the parcel sent directly to my parcel locker [1] and get an SMS when the parcel arrives. I don't need to be present.
UPS -> ??? means I'm guessing whether it'll be a local courier who has the contract or whether it'll be one of the many Toll [2] subsidiaries. No couriers are accepted into parcel lockers (unless you get a Toll parcel dropped off at a news agent).
Amusingly there are also those orders of things you don't care about getting immediately. Those seem to come fast, often less than 24 hours from ordering. Amazon doesn't know which items fall in which category (their media $1 credit is not worth it). Nor do they seem to notice breaking their own promises and proactively doing something about.
My memory of prior years is that the vast majority of items arrived within time, and that it has been getting worse over the last year or so.
I celebrate when Amazon misses its Prime 2-day shipping guarantees. That means I can complain and they promptly give me extra free months of Prime as compensation. Not sure why you don't get the same. They always offer it in my experience.
I always order stuff with at least a couple of extra days before I need the item so if you can't do that I could see why missing the 2 day target is bad.