I think we can all agree that NK is in a rough spot at the moment in Ranked. On the one hand, they are practically impossible to win reliably, causing many people to leave once they get them. On the other hand, NK as a 3rd faction that both the Town AND the Mafia need to deal with provides much-needed flavor in Ranked, and I don't think that simply removing them is the right way to go.
I would propose changing NK win conditions so that they can win EITHER by being the last faction standing OR killing a certain amount of people. Serial Killer and Arsonist would each need 5 kills to win, while Werewolf, with its lacking kill potential, could need just 4 kills instead.
Not only would this be a much-needed buff to NK's in terms of winning games, it would also be more thematic for the Neutral Killings to be rewarded for devastating the town even if they die in the end. This change also doesn't affect the OG NK wincon, so AA NK's will not be screwed over trying to get 5 kills in a town potentially full of killing evils. Of course, there is the potential problem of NK's going the route of Pirate, where they can side with town after getting their win condition to screw over the mafia. Then again, 5/4 kills would be much more devastating than 2, so maybe it's not a big deal? Overall, I think this change would make NK a lot more rewarding and fun to play. Feel free to give feedback!