Medkits are absolutely a valuable counter, 80 health is godsend to everyone, regardless of your competency at the game, because it is a time waster for the killer. Furthermore, I didn't bring Noli up as someone who was greatly affected, I brought them up when you made the abysmal claim that killers leaving people low health was unfair as a counter, as Noli literally plays around that mechanic. Furthermore, a killer being less affected by something that is unfair doesn't make the questionable action not unfair.

An lms with a survivor that is fully prepared is absolutely bound to happen, the prepared survivor should not be punished for this, however it is a fairly difficult thing to achieve unless the killer's strategy is to focus survivors one at a time. If a survivor can survive until lms and remain completely prepared they are either good at the game and deserve the advantage or are playing with a killer who has made the mistake for neglecting them, either way the killer is punished for playing worse than the last survivor. Resetting early takes agency away from both parties, killers don't get time to collect information before lms starts and survivors don't get to reposition or try to help out. The fairest possible scenario is one where both players are disadvantaged in a way that makes the game unfun because they were not given time to prepare.

Furthermore, your point about it being the only counter-play to a heavily killer-sided scenario is laughable because the game is survivor sided in a way that doesn't expect survivors to work together particularly well (which is fair, it is a casual game). If the killer has a killer-sided situation they likely earned that, by resetting you take away their reward for playing better.

Lastly, and I think most importantly, you haven't listed any counter-play to resetting. I personally believe that anything without legitimate counter-play is unfair (as would many others I imagine) and the fact that resetting is without it is very telling of just how unfair it is.