Coax can come close of the previous FCC gigabit goal. The FCC wanted 1 Gb/s down/500 Mb/s up. Xfinity is currently offering 2 Gb/s down over coax to most of their residential customers. They can only do 200-300 Mb/s up though.
This is changing with newer DOCSIS standards! It's still up to the network provider to choose how many channels they allocate for up vs down. Even in perfect lab conditions, DOCSIS 4 is still about 3:1 ratio down/up (about 5/1.5 gigabit). Fiber is the only medium that makes a 1:1 down/up possible at any meaningful speeds.
