Associate
He will.
Unless he is happy to settle for locked 60 fps with some settings reduced, I imagine he'll want to get as close to the 100hz/fps as possible though and he defo will need it for 4k/60
Maybe with RT, without the XT is perfectly capable of high FPS in many games. E.g. at the more demanding 4K res:
https://www.techpowerup.com/review/sapphire-radeon-rx-7900-xt-pulse/30.html
Fair enough if you're talking the very latest crop of titles, but the OP ruled out the very top cards and even they can't provide 100fps at 4k in some.
Having said that I don't disagree with waiting, it just depends on how long the OP can last on the 5700 XT. It's still pretty capable but that resolution is taxing.