[dom0]

ECC is often used without being advertised. For example, hard drives aren't advertised as using these kinds of codes, yet all of them do. Similarly, switches will often use ECC memory without making it an explicit point in the advertising. Industrial computers tend to have ECC, yet you will have to look closely at the data sheet to see this. And of course all internal busses and caches in pretty much any desktop/server/workstation CPU use error correction/detection.

The moral of this story is that ECC is only ever advertised explicitly, when it is special to have, i.e. because there are segments in the market where it is not used.

(A somewhat curious case are small microcontrollers. Often these control relatively important aspects of machinery, for example, drives [say a bit-flip in the drive controller turns STOP into RUN, which can get rather ugly on e.g. a lathe]; these usually don't have ECC. However, they are manufactured in very coarse processes and generally don't use DRAM.)