Very true. The audience has to see YOU doing the "main thing" live. Backing tracks create a wonderful sonic experience *if they are not the center of attention*.
How do you do that? It's not just about volume. It's about complexity of the backing when there is only a single person on stage. It becomes incongruent when they see one woman or guy performing and hear a 15-piece band.
Interestingly, you can get away with it for a BIG song now and then. But mostly, a solo person should stick with a small rhythm section, with a non-intrusive pad. You can do a LOT with that.
Also, with guitar players they can see your hands. Keyboard players should sit sideways so they can see you playing. Maybe even have a camera and a TV monitor where that can see "over your shoulder".
You have to be energetically "making music" before their eyes if you want a great "live show".
But I am a big believer in backing tracks, well used.