I touched on the 4090 example above, but you're lacking fundamental reasoning here - in order for a CPU bottleneck to be created the GPU first needs to be capable of pushing more frames than the CPU is able to process within a given period of time. To use your Helldivers 2 example (more on this later in the post), this is what that looks like for the 3700x when paied with a 4080 super vs being paired with a 4070:
As you can see, only the 4080 super is able to produce the required number of frames at 1080p in order to create CPU limited scenarios (hence the ladder effect across the chart as we move up through various generations of CPU's), with the 4070 it is
GPU limited across the board, even at 1080p.
please watch this:
If short on time watch the section from around 4 minutes to 7 and a half minutes in. No dips to the 40's at 1440p or 4k with a 3700x paired with a 4090, the same with the 3080ti. All of that despite being CPU bound. This is how it scales at 1440p with a 4090:
So unless the PS5 pro were to undergo a complete architectural change (meaning it would no longer be a mid-gen refresh) which would enable a jump to a 7700X or above, then any CPU upgrade they were to slap on the PS5 motherboard would result in insignificant gains. The dips to the 40's on the base PS5 are indicative of a GPU bottleneck rather than a CPU bottleneck based on the following:
Which brings me to my next point:
Consoles are about trade-offs, always have and always will be (in fact the same goes for most people building a PC, particularly those not fortunate enough to just be able to purchase top of the line parts across the board). The increase in performance gained at resolutions of 1440p and above is far greater going from a 2070 super (equivalent) to a 4070 than it is going from a 3700x to a 7700x on the CPU side. Even if you were to attempt to "balance" things by upgrading the 3700x to a 5700x (or equivalent) and only upgrading the GPU to one which is of similar capability to a 4060 (for example) then you are not gaining anything overall and you are using any upgrade budget you have sub-optimally from a performance capability standpoint.
For the CPU to be a major factor (to use the helldivers 2 example again) then you would need to be jumping up to a card that is of similar capability to the 4080 (which just isn't going to happen at sub $1000 prices). See the charts below which illustrate this.
3700x:
5900x:
7700x: