I challenge anyone claiming differences in ethernet cables passing packets. There can be zero differences because a bit is a bit. Bits just don’t get dropped or we would not have communication over the internet.
I don’t think this is the real issue on this thread. The different ethernet cables are transfering bits from the source. No argument here.
The destination is the audio system and the intent is to prevent noise, mostly caused by RF interference, from getting into the audio signal.
The signal distributed from a cable company which hooks up to our modem/routers is full of RFI, some ethernet cables are better than others in transfering clean data. Supra CAT8’s conductors are individually shielded which helps reduce interference/ noise from being delivered to the destination.
The major source of this RFI in our homes is the router.
Using CAT8, I experienced a lower noise-floor from my streamer than when using CAT6.
Looking to reduce this noise further, I went to the source and added RFI/EMI filtering at the router. My streaming playback has been greatly improved.
Using an RF "sniffer" device indicates no RFI coming from the router into my audio system.