Ceilings don't necessarily need to be low, but the less wall height, the less the walls can be a reflecting plane.

Absorptive ceilings provide (1) bulk absorption in a room and (2) reduce the primary reflecting path among open offices when there are partitions of modest height between workspaces. That they hide the mechanical and electrical crap from sight and make it very easy to service those items was supposed to be their benefit, but the pendulum has swung the other way and the "finished" look is boring now...