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.

UPS, FedEx, DHL etc., when they aren't just completely scummy (lying about delivering something when they haven't; lying about delivery charges), take far longer to deliver packages and often leave them in completely arbitrary places - in the middle of the driveway, for instance.

Essentially none of the major commercial delivery services in the US seem to know anything about actually delivering packages.