> Yep. Lets optimize for the 20%, let the 80% adapt by moving their phone further away.

What 20%?

Near-focus eyesight problems start in mid-30s for some folk, and are already noticeable in close to 100% of 40 year olds.

You're optimising for 45%, not 20%, while allowing almost 100% to view.

Doing it your way optimises for 55%, while allowing only 55% to view.