Guys why do you wear gym shorts under your sweatpants or jeans [And you're not even going to the gym or play sports] & then sag you pants so we see the shorts? Like why do you wear so many layers? Why do you sag?
The same reason women wear yoga pants everywhere. The reasons you may say or justify for wearing yoga pants is the same reason. Their comfortable, and they do what they do. But for real it is comfortable and relaxing to wear and seat pants gives testicles and the penis a bit more space to breathe.
I know which crowd you're kind of targeting with this one and most of the time it's usually guys who it just become natural for. At a certain point it kind of stops becoming this idea to be "cool" and they just find it comfortable and breezy especially when you sit down.