Every day millions of people all over the globe use them. They are on the move constantly most days, so we have no idea how many mile one does in a day. People get on and off, laughing and joking texting each other as they travel up and down floors, with no care in the world.
Yet to a small minority, escalators are a real phobia - I know - I am one of the unfortunate people. I only found out a few years ago, I was at the top of some stairs, and when I looked down I couldn't see the division of the steps. All I saw was a line of moving ridges; I get the same feeling on some sets of stairs, if they have the metal grids in them :(