That's the thing. I've spent many years watching Digital Foundry analysis and 99% of the time, I'd never spot the differences between console and PC versions of the same game (especially with the Xbox One X). The only real difference between the two is the frame rate and being able to choose your resolution on PC (the latter now being a bit moot as the Xbox One X is near 4K most of the time).
The problem I have is I am never happy with what I've got. For years I wanted a gaming PC, bought one and now a year later I'm bored with it and itching to buy new tech which is why I want the next gen to start already.
What you have now will last you another 2yrs even if you game at 1440p. 4K on pc imo is just a weird scenario as most monitors hit 60hz still. I've yet to see one sub £300 that can push past 60hz.
I recently upgraded and wish i never bothered. £2.5k and it doesn't even feel remotely worth it.