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.
For me it isn’t the waiting, it’s the “being around people” part that is physically draining.
I am happy to wait in a Zoom waiting room for example, because I can do it at home all alone.