What 144 hz monitor? 1080p? 1440p? 4k? Ultrawide?
What games are you trying to play?
Lean to overclock, the 7700k while having fewer cores still has speed going for it.
There won't be a bottleneck could you gain more performance with more cores and a newer generation of cpu well yeah of course.
Push the 7700k to 4.7-5.0Ghz and you should be fine. A decent match for the gpu, regardless of 1080P or 1440P
Moving to a 10th or 11th gen Intel cpu like the 11600k would provide a big gaming boost over the 7700k especially at the 1% low frame rate. If you want to move over to AMD the 5600x is an outstanding gaming cpu.
View: https://www.youtube.com/watch?v=L0qaZ85CpUM
Moving to 10th or 11th gen from 7th gen would require moving to a new platform, which the OP may not be able to do right now.
What upgrade would you suggest?