My desire to avoid the inconvenience of some extra driving (if I drive all the way to the destination only to leave because plans changed) is not more valuable than other people's lives.
There's no good reason to be on your phone while your car is in motion — absolutely none.
And yet... that's still a pretty minor inconvenience when weighed against the potential to cause people to die or otherwise be seriously injured. There's no valid justification for it.
> see if they're expecting you/changed plans
This is impossible with Android Auto, you can't read or send texts (without voice, which doesn't work properly in my car). It auto-responds telling people to phone me if it is time-sensitive (like changed plans).
If they don't call back I'll arrive late, big whoop, at least I'm not arriving in a body bag. If they have a problem with me being late, they changed plans last-minute. None of which has happened to me.
> do it the moment it has utility?
It never has utility.
Where is this culture where it's acceptable to change plans on a guest that is driving to your house while they are driving?
Going to 'somebody's house' has all but disappeared from modern culture, for most of the population. Maybe at Christmas.
Its a drug, the potential to optimize your plans on the fly is so attractive that even folks that swear they'd never text and drive, do it the moment it has utility?