It didn't sound too bad to me - especially the Witcher 3, as it's pretty demanding even today.
However, looking into it, yes, that kind of CPU load does look a excessive.
I'm not sure what's causing that, honestly.
Coudl you post a screenshot of Task Manager while gaming and reaching 100% CPU utilization?
If the culprit is the game, you're not going to be able to do much with that, other than lower (or increase) your in--game settings.