Yea kinda my thinking as well, but our local post office is super small and staffed nearly entirely by temps who don't seem to care much. The management there is fairly cooperative, but the people who tend to pick up our packages are often very "complainy". Which to be honest I can't really blame them, it's a fairly miserable job.
Totally. When shipped within the US it's probably a 99.99% reliable ship success rate. The biggest cause of lost packages "domestically" is just an incorrect address. The international "lost package" rate is a bit higher, but that's just kinda inherent to shipping anything over seas.