I think there is value in the destinction if it's only used as a storage backend, but actually gets the media through different sources.
To be clear, I have a deep appreciation for SciHub and LibGen, I just don't have the energy to dive in depth in this forum.
They didn't have enough storage for their full library on the appliances previously. So that'd be like a caching proxy in front of the service
Maybe that changed with how tiny their library became over the years. (Edit:it didn't change. That's what it is.)