Should brain surgeons not have kids in case their sleep is disturbed? Should they pop out a baby then leave it with their partner and move into a hotel until the infant sleeps through the night? What about brain surgeons who've just fallen in love and are besotted to distraction? Should they be allowed to operate? How about the ones who are caring for elderly parents, or who are recently bereaved, or are supporting their teenage kids through serious stuff in their lives, or the ones who have any aspect of their life which might detract from their performance at work? How about the brain surgeons who've had a kid with another brain surgeon? Should they each stop working until they are able to get eight hours' sleep a night? How many parents of pre-school kids get eight hours sleep a night anyway?
Brain surgeons are normal people with lives who happen to have a job where they operate on brains. If you'd rather the brain surgery wasn't carried out by a normal human surgeon who is subject to normal human life events, I'm sure you could choose for your child not to have that surgery, though you might be waiting a while for an alternative to come along, and perhaps you'd rather the surgery was performed than not performed. Surgeons are entitled to have lives outside of work. I'm sure it's shitty as hell when a child needs brain surgery; but there just aren't very many optimally-rested, unstressed and unimpacted-by-life-events surgeons, and if surgery was only carried out by such near-mythical surgeons, there wouldn't be much surgery getting done.
There was an interesting snippet on the What's Up Docs podcast, or perhaps it was on Doctors Notes, recently, observing that many people carry out many of the very important, impactful events of their life having not had 'enough' sleep - exams, job interviews, court appearances, high-profile presentations, that really important piece of work with the looming deadline... Tired people turn out to be pretty good at hyper-focusing on the thing they have to do, e.g. brain surgery, it's the other bits of life that suffer first - maintaining patience and good manners rather than snapping at colleagues, doing the life admin and household chores before/after work, making a packed lunch to take to work rather than buying a sandwich and coffee in the hospital canteen, summoning the motivation to go for a run after work. A tired brain seems to prioritise pretty effectively.