I wouldnt doubt the post office on privacysimply because any pkg tou send has its restrictions and those are selectively xrayed or pulled aside because. it looks suspicious and there are post office guidelines for suspicious pkgs.
Letter mail? watch a few ytubes on how letter mail is handled and you will see that its nearly impossible to tamper with.
There are dishonest postal carriers and mail handlers but they are not prolific and the post office deals with them swiftly.
That’s all good to hear. Trust me, I look forward to the day when I can finally cut ties to the WWW. I remember what it was like to not have all this and the only ties to the outside world was the telephone (rotary preferred LOL) and physically meeting people in a social setting.