Heavier games doesnt mean it will have better performance, as i said above, your cpu can produce a limited number of frames for example 150 fps, your gpu cannot produce this much it can only 120 fps this is when you will see that the fps is 120 and gpu usage is 99%, the other example is that your cpu can produce 150 fps but the gpu can produce 250 fps, this is when you will see that the fps is 150 and gpu usage is 50-60% in my example. Being limited by the cpu doesnt mean that the entire cpu must be 100%, games are very single threaded applications so you might be limited by the cpu even if it is used only 40-60%. If a cpu can produce 150 fps it will be able to sustain 150 fps no matter of resolution or level of detail, on the other hand if a gpu can produce 250 fps at low details at 1080p, at 4k high detail it might be able to produce only 40 fps (again your gpu usage will be 90-100% for 4k). In present you are limited by the cpu, thats why i said to raise little by little the level of detail until the gpu reaches 80-90% because you will not gain additional fps by lowering details, that is the limit of your cpu no matter what level of details you set. Having the gpu up to 90-100% usage doesnt mean you have better performance, ideally would be that with everything maxed out at 4k, with 144 fps to have as low gpu usage as possible, that means better performing gpu but in present it is not possible, no gpu can drive a heavy title at 4k max detail 144+ fps.
But as long as you get the desired level of details and the targeted fps why stress out? I wanted to play games at 4k 60 fps+ with everything maxed out so i had no choice but to get 2x1080ti, now i play any heavy title with 60 fps+ at 4k and everything on max detail (witcher 3 70-90 fps, Nier automata 65-75 fps, far cry(4 and 5) 80-90 fps, a.s.o.) i dont bother with gpu usage because most of the games i have vsync on so i limit my fps to 60 and ofc my gpu usage will be in the 70-80% area but i achieved my target.
What you just do is to set yourself a target and see what you need to obtain that performance. This is the time when i ask you, what is your target and i can help you, guide you, to obtain that performance.
@Phaaze88 he might be using some low-mid end cooler and the cpu cannot reach full turbo, also i dont think he OCed the cpu so this might hold him back a little. Now depends what he wants.