It'll depend on the game, but at 1440p even a 5070 Ti / 9070 XT can push decent frame rates with a 9900K.I might consider holding on to the PC for another year if it was getting the most out of cards of that standard.
for what it's worth i would get a radeon of some sort (eg 9060xt 16gb - if going to buy new) as it has less driver overhead than their nvidia equivalent