So the simple take-away from this article is this: Some games are more CPU dependent than others and the higher the framerate, the more important a CPU will become.
Conclusion:
If you are going to buy a highend GPU and will be gaming at 1080p, you will need a higher end CPU to match.
If you are going to buy a highend GPU and will be gaming at 1440p, you will still need a higher end CPU to match.
If you are going to buy a highend GPU and will be gaming at 2160p, you will still need a higher end CPU to match.
If you are going to buy a highend GPU and will be gaming at 4320p, you will still need a higher end CPU to match.
In contrast:
If you are going to buy a midrange GPU and will be gaming at 1080p, you will not need a higher end CPU to match because the GPU would not need as much performance from it's CPU.
If you are going to buy a midrange GPU and will be gaming at 1440p, you will not need a higher end CPU to match because the GPU would not need as much performance from it's CPU.
If you are going to buy a midrange GPU and will be gaming at 2160p, you will still need a higher end CPU to match because what a GPU can not do in hardware a CPU will often end up doing in software.
If you are going to buy a midrange GPU and will be gaming at 4320p, you will still need a higher end CPU to match because what a GPU can not do in hardware a CPU will often end up doing in software.
Hopefully, this will help simplify the choices for a few buyers.