PUBG is heavily CPU dependent, but will perform just fine on 2nd/3rd gen i5's - a 3770 should have no issues for 60FPS gameplay
As someone who played the game a lot (and built PC's purely to sell for PUBG, when it was more popular than it is now)
1. Work on those CPU temps. 70C at 40% load? somethings wrong there. Repaste the TIM, and clean the HSF.
2. Dont do silly shit like disabling the swap file, leave things on automatic and remove as many background processes as possible.
3. PUBG does use more than one thread, but its definitely CPU bound by single core performance - you *will* hit an FPS cap at some point on that CPU, tho it should be well over 100FPS as long as the CPU and the VRM's are not overheating
4. the 1050ti is pretty weak for pubg, so definitely keep the settings down low. Render distance at 100, 1080p or lower res, etc. FPS drops will happen on such a weak GPU, but it shouldnt stutter.