This is something i just found out last week. Most ppl who plays on laptop suffer from bad performance even thought they got very good GPU (In my case it was an RTX 2070). Short story, i used to play modern warfare on my Asus rog strix iii with the the rtx2070 and i had fps drops, low fps (80-100). After trying to clean my laptop, repasting, undervolting, overclocking GPU, and few other tweaks, my fps boosted to (90-110), but still i had other problems like stuttering, etc. Last week, i saw a video showing that using an external monitor boost your performance in most games (I know it sounds weird as this is a laptop, but right now i have to stick with it until they release the new generation of Nvidia). The reason was simply because of Nvidia optimus and how power is distributed, and even if you were using turbo/high performance mode on your laptop you will still suffer from bad performance. I tested it on an FHD 144hz external monitor and i easily got 130 fps (its capped on 130 because i am using HDMI cable).
If you are interested in knowing mode details check this video out: