Speaking as an optometrist and advocate for people who have all kinds of vision impairment, I agree with this idea, and would expand it to other componants of the user interface. Not everyone who drives a Tesla is 25 yrs old and has 20/15 vision at both distance and near. Sure, many people have great vision, but people have different visual needs for a variety of reasons, and if we assume that everyone can see 6 pt font with or without their glasses, we've limited the visual options of many drivers.
In my state, the visual acuity requirement for driving without glasses is 20/40 distance vision in one eye. There is no visual acuity requirement for near vision. When we're 25 yrs old, our eyes automagically focus from distance tasks to near tasks without us even realizing when it happens. When we're 50 yrs old, it's much more difficult to change our focus from far to near, and many people start wearing multifocals to see distance and near tasks. (Just wait, it will happen to you.) Have you ever tried looking through your multifocal (in the bottom 10% of your glasses) to see the time on the top of your center console? It quickly becomes a chiropractic issue!
The point of this would be to provide options for those who need or desire it. The volume control allows people with different hearing abilities to listen at the decibel level that's comfortable for them. An arc second visual acuity adjustment control would allow people to adjust the visual user interface to a level that's comfortable for them. Sure, that's a coding issue, but we already have great examples of computer programs that do it well.
I've often thought to myself that this issue won't be fixed until the day Elon sits down in his Tesla and realizes that he can't see the center console like he used to. If that happens on a Tuesday, it will be fixed by Friday.
