Good point! Something I have also thought on. It seems to me that developing a serious illness or injury is a very big ordeal to put your character through, because of it's life-lasting affects (not saying the other options do not have these as well). Losing a leg for example; that would be tremendously hard to deal with! And how your character reacts to this and grows could be very interesting development.
I haven't read many books that this happens to the MC, but I do know one where the MC grows from a somewhat meek/weak boy is forced to become a gladiator and eventually becomes very strong and bold, until he is an unparalleled fighter... but then in a later book he becomes crippled, receiving a serious injury to his leg (maybe that whole side of his body?). He can no longer fight the way he used to be able to, and also is no longer considered as handsome as he was.
On one hand, I really liked this because it was not the usual struggle the MC encounters. But there is also a downside; in a way, this also bothered me. He would get into a situation where he would have to fight, and I would hate it that he could not longer be the clever able fighter he was. As a reader, it is exciting and enjoyable when the MC can excel at physical and mental challenges, especially if they have developed these skills over the course of the book(s). If an injury or illness causes them to lose these abilities permanently, it can be frustrating, disappointing, or even boring because the best elements of the action is taken away.
I'm sure there would be a way to still write this effectively, but maybe that is part of the reason so few authors do it? Maybe they prefer traumatic experiences which do not later take away from their MC's physical and mental prowess, or more so only do so temporarily before the MC can make a comeback and be as good or better than ever at their skillsets?