Dude Descending a Staircase

Do we know why descending a staircase was once such a big deal?

Atop this post is recently uncovered footage of Marcel Proust doing just that in 1904 (he appears at the 0:36 mark, dressed in a lighter coat).

This is the only known footage of Proust.

What are the entrance mediums of today? Is it even possible to make an entrance anymore in this always already, ever-present world?