But companies still ship with them ...why ? cost ?
That company probably has an account with UPS, so yeah it's most likely a cost thing.
UPS has the Summit Racing account. We get multiple entire flatbeds filled with stuff from Summit every day. Regardless of how much frieght we get from Summit, Summit just pays a flat rate to UPS, which is substantially less than what it would cost to pay for everything individually. This is how Summit is able to pass along the savings to their customers.
P.S. It is entirely possible I have physically handled many of this forum members parts ordered from Summit!