I mean.. cat8 already exists but it will never be common because most people who dont make home networking a hobby just use wifi.

Hell many many people now a days own only a tablet and phone and no desktop/laptop at all.

Someone else in this thread mentioned motherboards with SFP ports on them and I cant believe that will ever be common because people can barely handle the many flavours of cables using USB C, how are they going to manage the mishmash of transceivers that only like specific brands and the DAC cables that may or may not work depending on how they feel that day.