[dragonwriter]

> If the answer is "offsite backup" wouldn't it be glacier or nearline or ... anything but S3 ?

Well, technically, S3 Glacier and S3 Glacier Deep Archive is still S3, Cloud Storage Nearline is similar, except it's a tier on Google's S3-equivalent service.

But lots of public charities, especially academic institutions, host data in a way conveniently accessible to the public via well-known convenient APIs, including S3, even when it is not the least expensive method possible viewed strictly from the cost of storage and institution-internal access because of their mission.