I'm almost never folding KK pre flop. In fact there's probably only 4 situations where I'd even remotely consider folding. And even in these 4 situations I'm probably not actually folding 99% of the time:
1.) If villian shows me AA pre flop. I actually had a villian at a live 1/2 game do this. He raises, I 3-bet him, folds back to him, he 4- bets me. I tank and he goes "I have aces, i'll even show you." He turns over one ace; i tank some more, he goes "You seem like a nice guy and a decent player, you wanna gamble we'll gamble or you fold" and turns over both cards for AA. I actually almost called even then but I basically had two outs so I folded. I have no idea why he did that to this day.
2.) If I'm on or near the bubble in a tournament and a KK fold will pretty much guarantee getting ITM and I'm not so short that it would be a waste. If I'm under 15bb I'd probably auto shove regardless of bubble, but if I was deeper stacked, I'd fold into the money then get back to building the stack.
3.) If I'm so deep in a cash game and villian has me covered I might consider a fold. There's a pro player, I believe The Iceman who has actually even folded AA before when super deep stacked because it reduces his variance he says. I don't agree with this move but if you're sitting like 5x+ buy ins deep and a villian with 6x deep shoves on your KK are you comfortable with
gambling with that much profit?
4.) There's multiple all ins already. Like situation 3 there's always a risk here in multi-way deep pots,. Again depends on risk tolerance and ability to deal with variance so I've seen players fold KK and even AA facing 3+ all ins ahead of them.
And honestly there's a big problem with situation 3 folds because it, at some level, indicates scared money or at least fear of losing said money. Folding isn't correct in nearly all cases of situation 3. And even situation 4 is a little dicey because when facing so many all ins, sure we might run into AA, but could also run into AK-1010.
Long story short it's almost never correct to fold KK pre flop in a cash game.