UPS had been consistently bad for a few years so we switched to FedEx at
Excellent Supply. Eventually, UPS added some massive new state of the art hubs, and FedEx slid behind.
Then the Coronavirus hit and consumers quadrupled their online shopping. The perfect storm! Presently all the carriers are being pushed past their breaking point.
Since FedEx has seriously declined we’ve switched back to UPS. In fact, they're now considerably better than FedEx. UPS is currently stronger and better suited for the maelstrom than the others.
Bottom line; the entire shipping infrastructure is in pretty bad shape. Actually made a video about this a few months back.