I also have XS hands and I’m not sure how you manage to hold an iPhone XR? I had to fight at work to simply get an XS instead of XR, and even then with my thumb I can only reach the right half of the screen, and I can’t get to the whole height of the screen.

Reading on a screen is effortful for the eyes anyway, so I think it’s more a matter of choosing your poison than anything else, to be honest. If a mini phone will encourage me to also be on my phone less, that would be nice.