I would have used that 3/4 times during the last year in a big EU city: we do consulting, and one of our customer is adamant their data cannot go on the public cloud. So they have their own data center, and some file sharing utility. Problem is, you need to go through their VPN, that is super slow, and their sharing utility closes connections after a while.
Result: transferring 30/40 GiB of data is painful, and we often go to their office to retrieve the data instead of using the Internet. In an ideal world, I wouldn't need a service like the one you suggest, but since a lot of our customers seems to be in the Stone Age, I would probably use it.
I have friends who do regular SSD file transfers. Mostly between different countries but sometimes in the same city.
They just use regular messaging services and simple of the shelf encryption software with out of bound key transfer (I.e email...).
Hardware encryption (and platform for key sharing and booking deliveries) could certainly be useful, but I’m not sure about the transport port. I feel like outsourcing it to normal transporters is more reasonable
For stuff that could not and should not be transfered over network.
I had this idea for a bicycle messenger & hardware encryption startup, but i don't have any idea what the demand really is like.