I didn’t watch the video, but it’s amazing how muscles are simply a matter of the right hormones and steroids that the body produces.
Because we have adaptive muscles, we humans assume that exercise is a necessary requirement for strong muscles. But all exercise does, in fact, is signal that the muscles are being over-used/damaged, and the body responds by sending more of the hormones that cause more muscle to be built, making you stronger.
If you just got those steroids, you would grow muscle.
So plenty of predators in the wild, or even in the lazy zoo, are packing some serious muscle without necessarily exercising much.
On the flip side, those muscles consume a lot of energy, and so our evolutionary niche says “if you don’t need them, don’t bother growing them.”
