Keep in mind that enthusiast cyclists are not sitting upright on their bicycles, like a chair. Their torsos are rotated 45 degrees or even more horizonally for aerodynamics. Their legs are constantly pedaling and pushing against the front of the saddle, so they look like they are convex even though the rider should not be sitting on that part of the saddle. Realistically, only the rear third of the saddle should bear any weight.