That is an absolute fact. Last summer dealing with my injury was a labor. Because of the injury I had almost zero ROM in my left forearm. So this showed me that even the simplest of tasks we take for granted can be a chore. I couldn't open a lid, hold anything with weight etc. And the hand had no strength and zero dexterity. I couldn't even touch my thumb and forefinger together.
So for me this crystalized the use of a WML on an EDC. I don't have a WML on every EDC, but I now make sure I have one reasonable choice. Why? Because back then I literally could not hold even a small flashlight in my support hand. There was no grip strength to hold the light. And even if I could, there was no ROM. The light would have been pointing in one single direction and that would have been it. So having a light source available and usable on the pistol itself demonstrated to my satisfaction to be a good benefit.
I had to change around the way I carry some of my normal EDC items so they would still be readily accessible.
Going back to the injury itself, at the time it happened. It hurt obviously but seemed like it started to numb up pretty quickly. I was able to drive myself to the ER which was only a mile away. Had it been out in a 'situation' it would have made everything far more difficult. Just moving around was painful. Trying to effect self-rescue would be a monumental undertaking. So illness or injury is definitely a reasonable and realistic factor to consider in any prep plan. Making things easier on yourself ahead of time is going to be time well spent.