The shipper entrust their shipment for the carrier in return the carrier gets payment for it. Hence, the carrier needs to be responsible from getting the good safely to destination. An effective business environment requires shipment to be on time and in the same state it was received. If carriers are not held responsible for most losses then businesses would have little trust to ship sold goods-stalling sales and growth of businesses.
In general for a bailment, the bailee has a lien over the item(s) of the bailment to ensure payment for the bailee's service.
Hotels have the most general lien; they can place lien personal property of guests'. Carriers have a lien on goods it is shipping for payment of shipping services. Warehouse has a specific lien on only a stated property that is being used for storage, to pay for storage cost.
B asked carrier I to ship item. I have a limitation to liability clause which limits their liability of shipment to $100 or a declared value given by the shipper. B declared the value for $500. The shipment never arrived to its destination, B claimed damages of $2,000 the value of item.
B will probably not get $2,000 but only $500 as the clause explicitly stated the amount owed as the declared value. However, I can't argue that they owed only $100 since they agreed on contract to pay damage up to the declared value amount.