Go over there, now get closer, now farther. Climb on that chair, now the stairs, go down the hill, hike that mountain. There are so many possible angles to take a shot and most of the people won’t consider any other alternatives. Many alternatives involve moving and going to places that require additional physical efforts. Sometimes, if you are on your own, you may need to carry additional weight. Camera and some other equipment are not always light. And even if it were, you could also find yourself having to run against the clock to take more shots.
Being a good photographer may require walking the second mile in a literal way. Why? So you can take an amazing shot from more different points of view, from a unique and challenging angle, from an exotic place, or from a far distance spot. If you are in good shape you will have better chances of accomplishing that and a lot more. But don’t think that you have to walk for days and climb mountains to get good shots only. Even in a wedding around the corner you need to move everywhere and very fast, crouch down, carry equipment and more.
If you have some physical limitations, you still can be a good photographer, but you would probably have to focus on that type of photography that require less physical movements. Don’t force yourself; you are not a machine. Every human has limitations. Don’t try to go beyond them. It is important that you enjoy what you do as a photographer. Don’t do more than what you shouldn’t.