I'm in murky water when it comes to computers. I won't waste a lot of time going into what I do and don't know, but simple explanations assuming I am stupid are ok.

(Note: I need to play on an external monitor as my eyesight is bad and the 15.6 inch laptop screen is too small for me)

I just got a good deal on a Zephyrus S GX531GX with a GTX 2080. I did not buy it for Overwatch, however Overwatch is my current go to game til I get my VR stuff.
Unfortunately, on the new computer, Overwatch is unplayable no matter what settings I put it on. It looks and feels like massive frame loss.

I am using a 60hz monitor. I have capped my OW settings framerate at 60, but no matter what settings I mess with, I still get this horrible stuttering that is unplayable, and, notably, far far worse than the gameplay ability on my old ROG with a GTX860.

Is it some kind of bottlenecking, even though I capped the frames at 60? It's just hard for me to believe or stomach that I can't play this game on settings at LEAST as good as what I had on my old computer, just because my new computer is too powerful.

If this is my issue, is there any way to play OW smoothly on a 60hz monitor with a laptop that has that much power behind it? I probably will invest in a 144hz monitor but I'd rather not right now if I can just play OW as smoothly as I did on my weaker computer.