Ethernet over HDMI is basically dead. Just because the standard supports it doesn’t mean the devices do.
It's pretty unlikely that you'll have ethernet over hdmi happening unless you go way out of your way to have it. It's not really something that just happens spontaneously, you need your devices to have it and the cable to support it. I think eARC canibalized the channels it used too?
At least with an Apple TV and a Samsung 900r, it is unable to network between the two.