Yet, it is our very intellect that recoils from cruelty.
Animals themselves don't really care about the suffering of other animals. Orcas eat the liver out of a still living Great White Shark (https://a-z-animals.com/blog/discover-how-killer-whales-sque...). Hyenas and African Wild dogs will start eating their prey as soon as they have immobilized it while it is still alive. If the prey is pregnant, they will rip out the fetus out the still living mother and eat it first.
Lions hunt in prides, and often while some of the lions are at the head, strangling the prey with their bite, the other lions will often start eating the belly, limbs, and genitals of the still alive prey.
A housecat will often prolong the suffering of its prey, "playing" with it, causing more and more injuries until it finally kills it.
Humans becoming more like animals would likely make us more cruel, not less cruel.