Not only that, but it's another mandatory system in cars that are already bloated with systems and features. More curb weight, more cost - both to purchase and to repair.
IF the standard goes that direction then automakers would probably need a little more compute but that's about it. If it mandates eye-tracking, breath or touch analysis, or anything like that then that will be a totally different can of worms.
Unfortunately existing manufacturers are unlikely to implement this in a local-first way.
[1] https://comma.ai
[2] https://github.com/commaai/openpilot/blob/master/selfdrive/m...