Why are humans the only animal to have such variation in physical attractiveness?

I just cannot understand this facet of evolution, it makes absolutely no sense to me. Why, when I look at any other animal, like bears, wolves, rabbits, snakes, squirrels, fish, lizards, birds, moles, worms and platypuses do they all have some semblance of continuity in physical attributes? Then when I look at human males and the disparity between gigachads and truecels they look like a different a totally different species to each other.

What is going on here? Most animals of the same species have at least the same skull shape and the facial differences are minor at most. A human can be 5’2 with a skeletal frame, potbelly and a bird skull whilst within the same species, even the same race within the species, can in contrast be 6’6 with a titan frame and a perfectly formed warrior skull. What sorcery is this? It would be a biological marvel if it wasn’t so ridiculously horrifying.