"I'm worried about her future, that's why I'm saving her mother". What the heck, you useless noodle, you wouldn't have saved that woman otherwise despite being able to? Imagine going to the ER, and they tell you "sorry, we could save your life, but you don't have kids so we don't have a reason to".
Those low-tiers authors should stop giving superpowers to their MC if they can't work out challenges to overcome without ressorting to stupid excuses like "If I use my power, medical knowledge will not progress". Just like Superman fighting crimes didn't render police obsolete all over the world, the MC healing every person in need he came across would make a dent in the need from normal medecine.