dish washer to sterilize jars for canning
Household Dishwashers do not sterilise, they only sanitise at best (with a 65° (150°F)). For sterilisation of all microorganisms including spores they would need to heat up to 120°C (250°F) for several minutes.
That being said you most likely breath in your own poop particles all the time, so sanitation may be enough.
Honestly, no clue, but in my career the answer why something beneficial hasn’t been done is usually “backwards compatibility”.