USPS has locked mailboxes at the curb (in cities). In apartment buildings, the boxes may even be inside the building. The other deliverers don't do that. I've never had a USPS package stolen, because they either deliver it to the lockbox or to you.

UPS/Fedex/FBA/DHL just drop it in front of my house and don't even bother ringing the doorbell. It rains here a good amount and if you don't notice your ghost package fast, maybe it gets soaked through.

Fedex has lied to me multiple times about attempting delivery on days they never did.