A 14" CRT monitor from The Olden Days has an area of about 523
cm². An iPhone X has a screen area of about 127 cm². A 5.8" screen is tiny, regardless of its resolution.
Resolution will only get you so far; people don't have infinitely acute eyesight and infinitely precise dexterity. Most people can't reliably hit a touch target of less than ~10mm in any dimension, which equates to ~180 real pixels on an iPhone X.
> A 14" CRT monitor from The Olden Days has an area of about 523 cm². An iPhone X has a screen area of about 127 cm². A 5.8" screen is tiny, regardless of its resolution.
People hold phones much closer than you would sit from an Olden Days CRT, too. It's not just raw area that matters, but something like degrees, as observed by your eye.
Resolution will only get you so far; people don't have infinitely acute eyesight and infinitely precise dexterity. Most people can't reliably hit a touch target of less than ~10mm in any dimension, which equates to ~180 real pixels on an iPhone X.