There is a reason why some (mostly US) sellers don't ship to PO boxes.
In the USA, couriers can be as cheap and fast as the PO, and offered free tracking too boot a couple of decades before the PO.
BUT
Couriers would not deliver to PO Boxes because the postal clerks would not sign for the parcels.
So those sellers refused to ship to PO Box addresses.
And newer sellers followed them without asking why.
And even newer sellers followed those without asking why, as the cost of tracking by USPS dropped and dropped.
It is now free when shipping labels are purchased online.
PO boxes are probably the safest addresses around.
Either the item is safely locked in the box or the owner must obtain it (showing ID) from the postal clerk.
Better than being left on the porch in plain sight as happens all too often.
