It's why elephants have thick legs and are barely able to move themselves, not to mention jumping. And spiders and ants have needle-like legs and can lift stuff many times their weight or jump many times their length.

It's also why there's no gigantic walking robots and anything large moves on wheels or tracks.

It's also why so many insects fly and flying drones and RC planes are easy. You can make a pizza box fly if you glue engine with a propeller to it. No engineering required. But big aeroplanes are hard.