There are a number of discussions on this topic. In my view, if you machine is working right it should get somewhat close to the max “turbo” spec. My top end is around 5.0. I think it hovers around a 4.3 range on one of my laptops with “Ultimate Power” running.
I think the max power of a few cores is key. There is the single main thread on a single core where GP handles most of the audio. But other plugins (and maybe other GP tasks) can use other cores. (Also if you use multiple instances of GP, you can use another thread of another core for main GP tasks on another instance of GP, as I understand it. So, that is a way to use other cores.)
But, I am not using all the cores on my (pretty powerful) Thinkpad. So, the number of cores can help, but is less important. The power cores are more important, but the efficiency cores can help by handling low power tasks without raising the temperature up (as I understand it).
I tend to think your spec may be okay (close call) if everything is working right (typical disclaimer: I try to pick up information in this forum, but others know much more than me).
I had similar issues and a fellow GP member (Frank 1119) saved me, twice. Actually I have been able to help others by passing on his suggestions.
I suggest you first try this: Resolving Crackling, Throttling, and "Ultmate Performance Option" in Lenovo Thinkpad P16 (Gen 2) - #56 by Frank1119