If you have a good 4k TV then go for it. You'll be pleased. However, if you run surround sound you'll also need a.4k capable AVR. And don't forget 4k HDMI cables (the XBX comes with one... they're not expensive, but they are different).
Regarding the future and buyers remorse... I see it the opposite way. I'd regret owning a 4k tv and NOT playing 4k games.
Also consider when the next gen comes, if it is 120 hZ refresh rate, THAT will also require a AVR upgrade for most users. Suddenly, the console itself seems like the least expensive part of the equation....
AVR: Denon X4400H 7.1.4; 80% gaming, 20% movies, <1% music
Speakers: Klipsch RP-450C; L/R Klipsch RP-250F; Side & Rear: Klipsch R-51M; Height: JBL 2.5" satellites; SVS PC-4000;
Platform: Xbox One X on LG E8 55" OLED
Room from hell: 16x16x18' open loft, thin walls, hard surfaces, lots of street noise