Artist my die'n butt.
Yes it it's a far cry from back in the day when you had people like Fred Astaire and Ginger Rogers who could do a dance routine in one take. Henry Fonda was famous for doing his scenes in one take. I've read that when they where filming The Godfather that it was so over budget that a number of the scenes where put in as they where made, ad lib.
Back in the day it was very expensive to film so you had to make do with what you had and only the best actors and actresses could cut it. I've always loved Walter Matthau and Jack Lemmon. They were so good together they could ad lib entire scenes.
I forgot to mention, almost everyone in Hollywood is related. Every time a new actor or actress comes on the scene I’ll look them up and I’ll be darned, almost everyone of them was born in the business.