Well no... they put a very fast (high refresh) gaming screen in a gaming laptop.
If you want QHD or 4K screens, they are out there. That's not... more than a Google away. So it's a really bad assumption to make.
Here, first google result for "Intel 4K laptop", it's $1500.
https://www.bestbuy.com/site/asus-zenbook-flip-15-q538ei-15-...
Your faulty logic was disproved.
Why in the world would you want a 1080p display just to get an extra 120 FPS? Even if you can perceive that difference (which I kind of doubt) you’re not going to get rates that high with your settings up high anyway. In The Verge’s tests only the old CS:GO got above 150 (it got over 400!).
“ In conclusion, putting a 1080p screen on this system is like sticking an MLB player in a Little League game. Sure, he’s gonna look impressive, but what is the point? These are 4K chips, and I’m not just referring to the price of this unit.”
Beyond that, one imagines there may be some performance and power overhead, and many hardcore high-FPS players will probably prefer a display that natively matches their target resolution. It eliminates unnecessary variables that might affect performance.