Amplitude panning dominates studio mixing because it gives compact, multi-listener images.

Evidence

Most image positioning during a studio mix is done with amplitude panning, IAD. It has been reported that amplitude-panned images are more compact than time-panned images, and as mentioned, there can be two well-localized hard-panned images at the loudspeakers for multiple listeners. — Toole, Floyd E, Sound reproduction- the acoustics and…, 408