Ambient occlusion node in material does nothing

Just curious why the AO feature would be removed, reduced or be on the table for removal ? When AO data conveys a huge amount of important visual data from ZBrush sculpts, especially for characters. This dramatically reduces the quality of a characters or creatures face for example. Forcing artists to bake this into the base color ? Sounds like a decision made by a programming person with little knowledge of how important AO is to the overall image of the artwork.