I wish I had your experience.
I don’t ship anymore, but USPS lost enough packages that I wouldn’t use them if I had the chance.
Now I receive pretty often, and USPS loses at least one package a year. If I have the choice, I always specify UPS or Fedex. They’ve never lost one of my packages.
For me, the speed of delivery is less important than knowing when to expect the package. I’d rather have a firm 2 days or 3 days then a 1-5 days.
I do have more reliable USPS service when I have my packages delivered to my office rather than my home...
I will say that USPS’s tracking has improved significantly recently.
Have shipped about 8000 packages per month this year. 75% USPS, the rest FedEx. Only get a few lost per month and the annual percentage of lost ones is about equal comparing USPS to FedEx.