Let me put it in another perspective: if you buy a 4090 and a 13600K you will definitely get a superb gaming experience, but in the specific use cases where consistency is king, you're better off going to a 7900XTX and pair it with a 5800X3D or a Ry7000X3D. You will even SAVE money doing that.
I'm avoiding any Intel comparison, because as mentioned it will just bring out the fanboys, and we don't need any more "my platform is better" beeswax. I keeping the comparisons strictly between AMD's offerings for this conversation.
I get where you're coming from, that VCache allows more frame consistency. I also agree with your purchase of an X3D GPU, as you already have a flagship GPU (at that time) and the only gaming improvement left is the CPU side.
But again, you ignore the inconsistency of X3D's gaming boost from game to game, which in my mind more than offset the improved frame consistency you experience. I would also again point out that most people don't have or can't afford a flagship GPU, so the question of "should I put money into a better GPU vs CPU" is more relevant to them than to you. Hence the request for a value proposition test.