https://www.pcgamer.com/capcom-explain-why-the-monster-hunter-world-port-is-cpu-heavy/
 
 The game is regarded as being rather demanding on hardware considering what is on offer visually. However, one of the major reasons for that is how Capcom's MT Framework engine, which powers the game, works. 
 
To eliminate interstitial loading during active gameplay, MHW loads the entire level into memory. In addition to managing assets loaded into memory, it keeps track of monster interactions, health status, environment/object changes, manages LOD & object culling, calculates collision detection and physics simulation, and tons of other background telemetry stuff that you don't see yet requires CPU cycle. This is in addition to supporting any GPU rendering tasks. When testing the game with the i5 2500k and a GTX 970 PC Gamer, noticed severe stuttering at medium settings.