Currently, one has an AVR which has to decode and re-encode loads of video formats/resolutions/refresh rates/colour depth encodings etc which can require up to 48Gbps of bandwidth (HDMI 2.1, although most manufacturers seem to be standardising on 40Gpbs).
Instead we could just let the TV handle it (it has to handle it anyway) and send bitstream audio to an audio decoder.
It seems to be mainly about cable management.
So, 8K at a higher refresh rate comes along and all of a sudden you need a new TV and a new AVR. I could be wrong, but so far it seems TV tech is changing faster than audio tech. We now have Atmos and DTX; is there anything else coming that an already-existing eARC can't bitstream?
Anyway, I'm just thinking aloud. I have an AVR with everything connected to it