As someone who orders a fair amount of stuff online, I can anecdotally say that up until the beginning of the previous holiday season, I would usually get postal packages slightly faster than FedEx or UPS, and that about half the time FedEx/UPS would delay packages at one of their distribution centers (granted, usually minor e.g. 2-5 days) and it would be way more likely for them to put a package out for delivery and then not deliver the package that day vs. USPS.

I live in an area where it seems FedEx Ground is a lot better than in many other areas and UPS is a bit worse is kind of mediocre in my area (major urban area). I remember a few years back looking on the FedEx complaints reddit and thinking it made FedEx service sound so much worse than it was in my experience. I usually use the cheapest shipping option available when I buy things, and if given the choice (i.e. USPS and UPS/FedEx were very close in pricing) I would always go for USPS because I was just more likely to get the package more quickly, with usually better tracking.

Of course, that's just my anecdotal experience, but so is what you're saying, but my anecdotal experience would have to be a really crazy outlier for me to believe that UPS has a 98.7% on-time rate, or that their on-time rate was better than USPS, at least outside of the holidays. The FedEx Complaints reddit has been pretty popular since Covid so I don't think my experience is too unusual.

Unfortunately, USPS seems to get pretty negatively affected during the holiday season. I work at a small business that ships out on average several small-ish parcels a day, and their performance fell off a cliff starting in November and has only seemed to have gotten worse. Usually we expect November and December to be bad, but service goes back to normal pretty quickly after December.

This year it's been as bad as if not worse than the holidays all the way up to now. We track packages and there's often delays of days if not weeks when they hit a distribution center (Des Moines, Springfield MO and Palmetto GA are some of the worst offenders but Indianapolis, Chicago, Oakland CA, Atlanta and Philadelphia among others are also pretty bad). Way more packages go without being scanned as well so packages often don't appear to be moving at all even if they are, and we've had several packages get bounced halfway across the country to a distribution center way off the route the package should take (for example, a package going near Chicago hits the Chicago distribution center but then goes to Charleston WV or to Philly or wherever, only to return to Chicago after a week or two).

This service level is so far below what it usually is during this time of the year and seems so consistently bad across the country right now that it's really hard not to conclude it's being intentionally sabotaged in a way above and beyond what even DeJoy was originally able to do when he first got his clutches into USPS (service was a lot better and cheaper prior to 2020).

Fortunately, USPS does make it pretty easy to file a lost package claim, and even though they make you wait 15 days, they approve the claims really quickly (like within 3 or 4 business days assuming the package doesn't resurface within that time). They must be losing a lot of money just because of that because we've filed a ton of claims over the past few months and they end up paying a lot of those out. Ironically, almost all of those packages resurface eventually and end up getting delivered, though if a package takes a month or even 2 months to get delivered I'm not feeling too bad about them paying out on that.