I have always wondered why DNA is an accepted evidence. It's so easy to contaminate a crime scene or bring someone else hair, skin cells, etc by mistake.
Because people believe it, and courts have accepted as fact that DNA evidence is infallible. Certainly there have been cases where DNA has been successfully challenged, but those are very rare. In the overwhelming number of cases where DNA evidence is present, it is a self-fulfilling prophecy for juries and judges.
If there is DNA evidence that is almost a guilty verdict. It should be more closely scrutinized but not everyone is rich enough to afford a real defense.
Which is weird, as you, the customer, don't have any leverage in enforcing any behavior of the shipping company (like make sure package is signed for). You can't even select them.
Apple for example charges you $9 for expedited shipping, which is essentially Uber delivery. But when the delivery person takes off with your $1,200 phone they don't have to replace it. It is on you: https://law.stackexchange.com/a/73842
When this whole thing is flipped around, where the sender is responsible until the buyer actually has it in their hands the whole system all of the sudden becomes incentivized to minimize losses.
(sidenote: it is a disgrace that Stackoverflow doesn't allow you to turn off auto-sharing of your ID when you share a link).