Question

If the T-Rex's arms are so short why is it useful to the huge creature?

Answer 1

Maybe because there wouldn't be so much weight on it's upper body so it wouldn't act like a dog, both feet and arms on the ground

Answer 2

Because first it's not so much wait on him and second they don't use there hand as much except to get food for there children as they are young sometimes and the children can't reach the trees so. Yeah