"These price increases have multiple intertwining causes, some direct and some less so: inflation, pandemic-era supply crunches, the unpredictable trade policies of the Trump administration, and a gradual shift among console makers away from selling hardware at a loss or breaking even in the hopes that game sales will subsidize the hardware. And you never want to rule out good old shareholder-prioritizing corporate greed.
But one major factor, both in the price increases and in the reduction in drastic “slim”-style redesigns, is technical: the death of Moore’s Law and a noticeable slowdown in the rate at which processors and graphics chips can improve."
Just to add to this, the reason you only see shared memory setups on PCs with integrated graphics is because it lowers performance compared to dedicated memory, which is less of a problem if your GPU is only being used in 2D mode such as when doing office work (mainly because that uses little memory), but more of a problem when used in 3D mode (such as in most modern games) which is as the PS5 is meant to be used most of the time.
So the PS5 having shared memory is not a good thing and actually makes it inferior compared to a PC made with a GPU and CPU of similar processing power using the dominant gaming PC architecture (separate memory).