If I had to guess, and this is just a guess, so take it with a grain of salt. I'd bet most storage devices these days are just thin wrappers around PCI-Express

If I had to guess, and this is just a guess, so take it with a grain of salt. I'd bet most storage devices these days are just thin wrappers around PCI-Express lanes, most of the hardware in the silicon running that stuff is on die for AMD/Intel CPU's and you likely run into cost/power/board space limitations in a device like this