Given the current RAM and disk sizes, and how much we put trust on computers, every cell phone or computer should use ECC RAM and checksummed filesystems these days.
The density/process size of the RAM would seem to drive that as well. A cosmic ray, for example, has a better chance of flipping a bit on a denser collection of transistors. Assuming the die size is the same, due to the total amount of RAM increasing, as you mention.