Because life is too short for jagged edges. If you’ve ever tried to cut someone out of a photo and they ended up looking like a cardboard standee, feathering is your new best friend. It’s the secret sauce that makes composites look real.
Think about it: nothing in the real world has perfectly sharp edges. Not your hair, not a fluffy dog, not even that slice of pizza you’re about to eat. Feathering is Photoshop’s way of saying, “Hey, let’s be natural about this.”
You want to put your friend’s face on a baby’s body? Feather it. You want to make a glowing light effect? Feather it. You want to feel like a professional? You guessed it—feather it.