>This hilarious because the mini still has a fair screen size of over 5 inches. I use a 4.7 inch iPhone SE for work and I watch content on it all the time.

Not really because you can't compare screen sizes like that when the screen ratio is different. The 12 Mini shows identical amount of content in terms of width as the old 4.7in phones (375px), it just has more height (which is somewhat negated by the safe zones).

The old Plus phones (5.5in) showed significantly more content on screen than the 5.4in Mini because of the ratio differences (12.9in^(2) vs 11.1in^(2)).