>>358311Humans, theoretically, could regrow body parts. But because that could take a long time, evolution did not find it a desirable trait. Instead, we quickly deaden the nerves and scar tissue forms fast, thus stopping bleeding, infection, and other problems.
Scar tissue was better for ancient people - they could survive longer and have a fighting chance, while regrowing limbs would take a shitload of time and you'd bleed out long before.