Spwculation:
Elaborate hair styles, including curls, might have been time-consuming/expensive. Wax head cones would melt in the heat and coat the hair to preserve the styling, like hairspray.
Fragrance dissipates over short periods of time, so lack of fragrance isn’t definitive. Unguents (animal fat/lanolin) would have melted too quickly for any class of society in near-equatorial heat and in any event, would need wax added to hold any shape in that climate. Not to say wax and unguent couldn’t have been mixed together as they are in Chapstick.