Oh, THAT’S why!
Now think about your sink. It’s elevated from the ground, it’s small and cozy, and it’s sturdy enough to support the weight of a human (let alone a cat). This makes it an ideal hangout for your kitty! From this tower of dominance, your cat can easily hunt the bar of soap in your shower or keep away from the vicious predator that is your vacuum cleaner. Sinks have become so popular with cats, there are even fake sinks for your cat you can buy online! You install one next to your personal sink so you and Mittens don’t have to share one.
Dr. Tu adds that cats love sinks because of their body temperature. You see, cats have a higher temperature than humans’. This means they favor places that can help retain that temperature. Concave sinks help cats conserve the body heat they lose.