Got it! Ethernet uses balanced pairs, which by themselves have some form of common mode rejection, but twisting it greatly reduces the harmful effects in the ca

Got it! Ethernet uses balanced pairs, which by themselves have some form of common mode rejection, but twisting it greatly reduces the harmful effects in the case where one conductor is closer to the EM interference. Twisted balanced pair has a lot of loss at >1GHz, at which point using a confined EM space in a coaxial cable can help prevent that. Ethernet stays under 250MHz, while WiFi is >2.4GHz, hence the cable differences. As another parent mentions, all changing currents produce EM waves, it's just the losses are much more important as the frequency increases. The following page helped me understand it as well. https://ham.stackexchange.com/questions/6445/why-isnt-twisted-pair-used-for-feedlines https://ham.stackexchange.com/questions/6445/why-isnt-twiste...