That's fine for regular ARC which is basically the same capability as spdif, ATSC audio and DVD audio. But there's no consumer audio cable that has the capacity for lossless surround except for HDMI, and then you really want eARC because otherwise you have one HDMI running from the receiver to the TV for video (and maybe audio) for sources that can go through the receiver, and a second HDMI that runs from the TV to the receiver for audio only for sources that can't go through the receiver (built into the tv like the tuner, network streaming, and playback from USB; and also devices that exceed the HDMI bandwidth of the receiver or don't negotiate to an appropriate video and audio format unless going direct --- I have a 4k Roku and a 1080p BluRay player that need different settings on the TV to work through my receiver, or I can wire one source direct to the TV and use eARC)

Wait until you find out that many consumer sound bars (Sonos comes to mind) only support the latest and greatest digital audio formats over eARC.