I find waiting for things physically exhausting. Waiting in lines, waiting sitting in a room, waiting on friends to decide what they want to eat, walking really slowly with an elderly relative: I find it all physically exhausting even though very little physical energy is required.
I don’t find it physically exhausting but definitely mentally and spiritually draining. (“Hurry up and wait” in particular is a rage-triggering thing for me.) I learned to adapt by always carrying a book with me that I can pull out and start reading while others around me dither and force waiting periods.