I think congestion reduction is probably the more common goal [1] from the point of view of the environment, economics and road capacity utilization.
Traffic calming is probably a localized goal in more pedestrian heavy areas or where there is a vulnerable population (children, disabled, etc.).
Traffic calming also benefits retail stores. I once lived in a city with an artery with unsynchronized lights. Getting to the other side of town was an exercise in frustration, but I can imagine the brick and mortar stores along it benefited from patrons making impulse stops. (I could be remembering wrongly but I believe they lobbied for the lights to be unsynchronized).
Traffic calming is probably a localized goal in more pedestrian heavy areas or where there is a vulnerable population (children, disabled, etc.).
Traffic calming also benefits retail stores. I once lived in a city with an artery with unsynchronized lights. Getting to the other side of town was an exercise in frustration, but I can imagine the brick and mortar stores along it benefited from patrons making impulse stops. (I could be remembering wrongly but I believe they lobbied for the lights to be unsynchronized).
[1] https://en.wikipedia.org/wiki/Traffic_light_control_and_coor...