In this case, your assertions that Intel, and even more so AMD, allegedly cannot make 128-bit controllers with a frequency of 6400 simply do not hold water. Since Apple can provide such super speed in their laptops (although I have never seen such numbers anywhere and first learned them from you, so I still need some official proofs), then for AMD, at least with TSMC, this is not a problem, not to mention for Intel. But we have, in fact, a shameful memory speed in all x86 processors without exception. 10 times worse than Apple in average. That is why both Intel and AMD, as I have already written many times, are desperately increasing L3 cache (which Apple does not really need to do at such a speed)
With what it can be connected? Bad development teams for x86?