Question about CPU Bottlenecks & G-Sync

[Jax765]

OS - Windows 10
GPU - RTX 3080 Eagle
CPU - i7 6700K
RAM - 16GB

I recently upgraded to an Acer Predator XB271HU monitor from my old Asus MX239H. So that's a jump from 60hz to 144hz, along with the gsync integration. I've noticed that certain games, such as GTA V or Yakuza 7, have worse stuttering issues since that upgrade.

My CPU usage is also very high when playing them, presumably because it's a bottleneck for my GPU at such high framerates. But even when setting the refresh rate to 60, they still don't seem quite as smooth as they did on my old monitor. I actually connected that monitor again to double-check, and the stutters were indeed less noticeable. The blurbusters refresh rate test also indicated that it was just over 60hz, whereas the new monitor, when it's set to 60hz, is actually 59.87hz. I'm unsure if the less obvious stuttering on the old monitor is due to the slightly higher refresh rate at 60hz, or because it's a much smaller monitor (23 inches vs 27 inches).

So I have 2 questions:
1) Is G-Sync is meant to smooth out these potentially CPU-related microstutters?
2) Would a CPU upgrade to something like the 5600X likely address this specific issue?

 

[Jax765]

My GPU utilisation isn't low, but CPU utilisation is generally considerably higher than it was when paired with my old GPU (upgraded from a 1080 to a 3080), especially when playing at higher framerates than 60fps. It's not that I'm getting low framerates, rather there's an increase in microstutters when playing certain CPU-heavy open world games which weren't as obvious before.