The Philadelphia Story was released in 1940, near the start of World War 2. The country was trying to pull together to face the combined threats of the Axis powers. George Cukor, it seems to me, directed the movie to imply the wealthy really aren't that different from you and me, in fact they are, like the Cary Grant character's boat, kinda yar.
Coming to the movie with a different lens, here are some of my takeaways.
The wealthy live in nice houses.
They like to throw big parties.
They have lots of help for their favorite activities.
They like to drink... a lot!
They are obsessed with social status.