The question you should ask yourself is : What other games will I use the next few years ?
The other question is, will the next Monitor be of higher resolution or require high FPS for some games ?
I fly in IL2, and casually rumble in War Thunder Tanks.
The WT had little problems with my 1080 card @ 2k resolution, but IL-2 game was an unplayable slideshow.
After changing rig, everything run smooth