"I'm all for fighting the good fight, but I don't care how much you work out or how much cream you put on-things change." Cindy Crawford, as an ageless robot applies some tonic. [Allure]
That is, if the robots are made of indestructible material that won't harden and crack over time. Anything rubbery and soft will corrode the fastest, and since it doesn't shed like a living thing does, it'll look even shittier than any old person can at the end. How's that wire frayin' treatin' ya canner!