I believe there is a decline. Holding a door for anyone behind you, or for someone about to exit is something I was taught to do. These days young men don’t even have the courtesy of saying thank you.
A few years ago as I was walking from the DC Metro subway stop into whatever the adjacent hotel is, I noticed that the young lady behind me was carrying way to much stuff to navigate the door efficiently. I smiled and held the door for her. Instead of saying "thanks", she said: "you must be from Indiana".
I am from Indiana and considered it a charming compliment.