Most companies and their parts suppliers are in cities, wherein there are any number of efficient modes of transportation - to the point wherein 'a drone' wouldn't even make logical sense, let alone economic.
There's going to be a considerable overhead associated with operating them - control centers, NOCs, etc. etc. so it might very well be that the 'lack of a human' is the real differentiating factor, i.e. safety, risk.
Nobody is going to be flying 'fresh ingredients' anywhere on those drones, there are regular planes for that as well.
So the use case of 'landing on a moving sheep' is probably right up their alley: it's remote, far, and landing on a moving ship is very dangerous. So it might be the killer use case for something like this. Remember the ship would have to be fitted with a permanent lading spot, trained crew etc. etc. so it would have to be used for something needed consistently.