They do. Thats what you have a gpu for. However as I stated source engine is really poor at utilizing gpu.
You can try it out yourself
-> Open task manager and look at your gpu & cpu usage while playing around with CS resolution. Gpu usage might increase like 10 % while cpu usage jumps much more.
Thats the issue. Even some rather new cpu's struggle to generate big fps on cs because of the fact that cs benefits from good single core performance and a lot of newer gen cpus focuse more on multicore performance.
"The CPU doesn't care which resolution you play on, 480p or 2160p there is no difference."
There is because you're comparing 4:3 res to 16:9 one. 16:9 has higher FOV, thus fitting more objects in screen for CPU to process draw calls from.
same, even tho my monitor is 120hz 1280x960 just feels weirdly better than 1400x1050
i think the monitor just has less to chew so it delivers faster on lower and lower res but 1024x768 is unplayable on mine because it blurs out