The game uses only 2 cores, that's why CPU uses is 50% or less causing bottleneck in the system even with a High-End GPU you won't get high Performance because your core frequency is too low and your CPU can't fully handle all the power your High-End GPU has. That's why players face stuttering in-game even with high FPS. All this can be fixed if the games uses all CPU cores.
PC specs
OS - Windows 10 Pro 64Bit 1809 os build: 17763.195
CPU - Intel i7 8750H
Turbo Frequency (cores)
4.1GHz: 1 - 2 Cores
4.0GHz: 3 - 4 Cores
3.9GHz: 5 - 6 Cores
GPU - Nvidia GTX 1070
Memory - 16 GB Dual Channel DDR4-2666
Storage - WD Blue SSD 540MB Read/520MB Write

Similer Problem -