Technically you can reduce any amount of bits to 1 bit if the compressor/decompressor agree about what informations that bit means. So there would be the full data on client-side/server-side, and you can "communicate" the finale desired data with solely 1 bit. (it's like the blockchain algorithm)

This sounds trite/heretic but it is as fundamental in its nature as the concept of "incompressible data". I agree that you cannot spare any data in the absolute, but I argue that you can communicate information with less bits than the data holds if the peers and the "model" incorporates knowledge about what kind of data is being transmitted.