People need to stop being lazy! If you cant sing a note well, practice and practice until you can. If you cant be bothered to sit around through 100 takes until you or the performer hits the right note, then in all honesty you shouldn't be producing. Auto tune to correct the odd note, yeah I get it. sometimes you get the perfect take but have a note out of shape. Now its at a point where artists are produced cause they look good over the fact that they are a good . . . artist, thats when I get pissed!!
I don't get it....
You say you get the thing about how it's OK fixing the odd note...but you also say it's lazy not to want to sit for 100 takes???
Mmmmmm...have you ever really sat for 100 takes in a row of the same track???
I guarantee you will stop before you get to 50.
That is a TOTALLY mindless waste of time and energy!

First off...it you can't get a *solid* 3-5 takes right off, I would stop and move on to something else or sit down and work out why you can't get a solid 3-5 takes right off.
But if your first few takes are solid, with only a glitch here and there....OK, if you want to try for a few more to see if you can improve, fine, but after a dozen or two, and it's NOT imporving...doing another 80 takes isn't going to help much.

You reach a point of diminishing returns becuase as you fix one part, now the rest of the take is starting to sound stale/tired...BECAUSE...the performer is getting tired!
There's a natural "curve" for doing takes....someone did a basic overview awhile back.
It goes something like...
During the first 3-5 takes, everything is fresh and it has that "first take" natural energy, then things will start to slide off if you keep doing more takes. Now, for *some* people, if they keep going, they may get a "second wind" somewhere around the 20th take, but then after that it just rolls off.........................
Your voice gets tired, your hands get tired, your brain gets tired, your ears get tired....how's it going to improve at take 100???
I would rather move on to something else and come back to that track the next day or several hours later rather than beating on it for more than a dozen takes in a row.