> How do you think it would be electrically connected to the CPU?
On the CPU's PCIe bus. NVMe drives are PCIe devices, designed specifically to facilitate such interfacing.
Edit: Pardon, misread the actual statement you responded to. Of course one shouldn't hook NAND directly to the CPU. I'll leave my response for whatever value the info has.
Same thing with DDR5: the electrical layer is a beast, it's a reason enough to require its own controller.