Very situational, I live in Telluride, CO, which, well, if it doesn't make the single contractor Swearingen Metroliner that leaves KDEN in the morning, drops off a container at KGUC, onto KMTJ and to the UPS Customer Center for loading onto a package car that has a 1.5 hr drive to even start deliveries, forget about it.
Not just physics (e.g. you're not getting another flight from KDEN to KMTJ until Monday AM), but there are literally not enough package cars and drivers to have any recovery. If it's not there by 6-7AM and on delivery vehicle by 9, you're not getting it, and you can't goto the UPS Customer Center to get it, either, because of staffing.
I suspect in larger markets the situation is better, but post-pandemic, with labor as tight as it is, I am not sure UPS (or any delivery company) has anywhere near the excess capacity for recovery situations. The package just gets punted to the next delivery day, really.
In our local area (and CO in general), UPS has been far better than FedEx. FedEx's staffing issues are, very, very bad. Our local route's FedEx driver has been driving his personal vehicle with a sicker b/c apparently his truck has been in maintenance for 2 weeks now, and, I hear they just laid off half the local drivers, who were already overworked.
Don't want to get into an off-topic/political discussion here, but what I will say, is it's interesting to see this happen yet see Fred Smith (FedEx) take home a total comp package worth over $10M and Carol Tome (UPS) do the same. But look at package car driver pay, sort associate, etc pay...the multipliers are out of control and it makes sense we see the issues we do with absolutely zero margin for error in day to day operations (nothing against management or C[whatever]s, I am an officer of a company myself, but my or my fellow CxO's don't have 100x+ multipliers to our lowest paid rank and file W2 employees, either....and we can actually manage to hire and maintain and retain staff at even our lowest entry level positions, really weird how that works...).