I'm sure it isn't (and, my condolences; that must be awful for you and even worse for her) but ... would you rather she didn't have an oncologist at all? (That's what happens if you just get rid of the sixes and change nothing else.) Or that she had a seven, who's working 80-hour weeks and working like a six on account of exhaustion? (That's what happens if you geet rid of the sixes and expect everyone else to pick up the slack.) Or that she had a seven but someone else with similar problems got her six instead? (Actually, I bet you would prefer that, and I don't blame you, but it wouldn't be any improvement for society as a whole.)

Having everyone be more competent would be a wonderful thing, but that isn't something you can bring about just by firing all but the best.