Well, those bugs you talk about aren’t game-breaking to me - and maybe to most top players - because you learn to and plan to work around them. Like, most pro players get to a point where they won’t attempt to do pacifications on stairs or on uneven ground because they know there’s a high risk of it turning into a noisy karate chop instead.
And you learn that even if a door has just shut, to wait a few seconds before doing a pacification because there’s a high chance NPCs can magically see through the door for a few seconds after it shuts. (I’m looking at you, entrance to sauna area in Hokkaido.)
Ditto on sniper shots. You learn to factor in being far enough away and allowing yourself time to get out of your sniper nest and take a route that avoids where the guards are coming from.
But for me, hearing the same voice over and over, that is game-breaking because, as @_Id says, it makes you want to just not play the game.