I'll also suggest that there needn't be some super-giant maximum capacity to dwarf our standards today.
Just as we have different size SD cards and USB drives, I'll bet there are varying sizes in ST. And some of them are probably just small to average size capacity, appropriate for whatever data it holds.
Like today, not every micro SD card is 64GB. Some are much smaller. Not every device needs to be the maximum technological state of the art. Same with ST.