You do not want cpu and gpu to run at 100%.
Normally, they alternate quickly and 100% use of a resource makes that resource a limiting factor.
Squad is mostly a single threaded game.
As such, you are probably only using a few of your 12 processing threads.
As a test, reduce the resolution and settings of your game.
If your fps does not improve then it indicates that the cpu is not sufficient to drive the gpu to it's capabilities.
As a quick test run the cpu-Z bench on your i7-8700.
You should see a single thread rating about 506:
http://valid.x86.fr/bench/bi01bq