British actors are odd in that they actually allow themselves to age--and continue acting till they die. It's just that their roles change.
Take three grand dames who appeared together decades ago in a TV performance of Shakespeare's Midsummer Night's Dream. Judi Dench ("M")appeared as Titania; Diana Rigg, later to gain fame as Emma Peel, played Helena; and Helen Mirren, AKA Queen Elizabeth, took on the role of Hermia.
Now they play senior citizens
American actors, on the other hand, try to cling to the type of roles they first had when they hit Hollywood--young roles. And discreet trips to the friendly neighborhood plastic surgeon accommodate them. Think of Demi Moore, Pamela Anderson, and Priscilla Presley. And names like Jennifer Anniston, Eva Longoria, and Angelina Jolie are following suit.
Then there's Betty White.