Humans are bi-pedal animals who walk extensively over long distances. However our feet are soft and not well suited to the task. However dogs, monkeys, and other animals have paws that serve as shoes to protect the feet.
No other mammal has such unprotected - but we are known for walking the farthest distances / nomadic behavior. Is this a joke?
It's just you. You're weak, and soft, because you've been trained by society to wear shoes.
There are many people who never wear shoes, and they have tough soles. From indigenous tribes, to modern Olympic athletes.
That said, even your dog can step in sharps and hurt their feet; cuts, thorns, stabs - shoes provide protection that paws and tough soles do not; this is the main reason we wear footwear.
If you're interested in a more back-to-nature approach without giving up extra protection, there are dozens of companies that sell minimalist footwear - in essence, modern moccasins. Vibram is one such, but there are many more. Fitkicks is a cheap version (~$20). Look for "active" and "water shoes."