You think sakura will cure mighty guy

[InfiniteMugen]

There are more pressing matters tbh, Gai is well beyond his prime, he is good to be retired. His foot was probably a blessing for him, the series implied multiple times that his "youth" was just an act.
They probably could've put him in a katsuyu chamber and healed him

Could of, should of, would of, fact is they didn't. And really femme? 10+ years of constant more pressing matters in a time of peace?