I share your frustration unfortunately.
I have ordered a few thing lately and they are/were shipped USPS.
Extremely slow is putting it mildly.
The tracking shows that it sat in Memphis for 4 days.
Then it left Atlanta 3 days ago and has not gotten to any destination.
So, I guess the mail truck is circling Atlanta on I-285.
Not to mention that the package had to pass by me to get to Atlanta from Memphis.
I deal with USPS with my job and it seems that all aspects have gotten slower.
Sorry for your frustration.