>>82893096 (OP)
The glutes and the hip in general is the surest indicator of physical fitness. The majority of musculature in humans is in the lower body, specifically the hips and upper legs. If you are weak there you are extremely prone to injury, especially as you age, and you are generally feeble and incompetent. Healthy hips correlated precisely to general health. Of course this is even more important in women due to childbirth.
Humans are meant to walk, climb, squat, and hunch down, all of which exercises these muscles rigorously.