Heaven1cent I have a 2600x + 1080 and I game at 1440p. To me it's fine. 80 - 100 fps ultra 1440p is my averages in games. I have a 165 hz monitor so I personally would love a 1080 ti, but there's absolutely nothing wrong with my cpu and gpu pairing. I've had compliments on the choice of 2600x and 1080. The 2600 is absolutely fine as well, you don't need the 2600x. With a good cooler my cpu stays turbo'd to 4.2 all the time. Ryzen 5 2600 is great for just gaming, browsing and media. If I was a streamer or creator I would have went 2700x. https://pcpartpicker.com/b/jRRJ7P
Heaven1cent I wanna add that if I had to rebuild and I was committed to not getting a 1080 ti then I might look into one of the best 1070 ti's since they can be very close to equal to a GTX 1080 for alot cheaper currently. 1070 ti can game at 1440p fine. A lot of people say that 1070 ti is the best value right now. I would look for one of the highest boosting ones from the vendor. I got my 1080 for a bit under 500$, but I can't find any new 1080's on a good sale. So if I had to put my system together again I would get 1070ti or 1080 ti.