Agree with all above
Just like to add, most games nowadays are multi threaded. Actually games since 2016 and some earlier have supported multi core/ multi threads. Saying that an i7s Hyperthreads will help. 2600 should run a 1080 decently enough even on pcie gen 2.
Also agree on frame rates mentioned above. The more fps you get the more cpu usage there is to feed the graphics card.
Even though games are becoming more and more multi core/threaded friendly, they're still heavily dependent on that primary core. Extra cores is a tremendous help in games today but Hyperthreading has shown it can go one step further in aiding that primary core with heavier loads especially at higher frame rates.
Watch this, if 8600k had HT, it's usage wouldn't be as high. Could say 8600k is overrated when high frame rates is of concern.
[video="https://www.youtube.com/watch?v=Qo3EJzHuXok"][/video]
As said, dont aim for too high fps and you should be right. Increasing graphics to reduce frame rates or use a program like Afterburner to cap fps to a certain amount. Just keep an eye on it, Afterburner also has the ability to show real-time stats while you game.
[video="https://www.youtube.com/watch?v=mUS3zx0DlHg&t=158s"][/video]