My nephew is in a similar jam. His specs are a little lower with a 1060 and a gen 6 i5 and a 1080p monitor.
Bear with me a bit here and youll see where im getting.
I told him his system is balanced for1080p gaming. The most he could do is maybe buy a higher refresh 1080p monitor. The next step up would require a big step up of everything to entry 1440p. Cpu, video, and monitor.
Your 1080 is a mid range 1440p card. I assume you already have a 1440p monitor.
A base 9700k or 3700x with a 5700xt, 2070 super will keep you on 1440p territory with faster frame rates.
3700x $315
X470 board $140
3600 16 gigs memory $110
2070 super $510
1440p 144hz monitor $500
So about $1575 for a modest frame rate boost.
Your next step up is 4k. And unless you are willing to spend ungodly sums on a monitor you are stuck at 60hz for $500 and a $1050 for the video card (2080ti)
So $2115 for 60hz gaming on a 4k
Now you need to decide which you want.