Yet doing more is exactly what you can do.
Picture in Picture video works perfectly on the 12 mini as it does on the pro.
You’re forgetting iOS doesn’t CHANGE due to screen size.
The spacing between objects you interact with (Home Screen icons, text spacing, video (picture in picture or full screen), so called touch-targets for text selection, keyboard, etc are ALL relative to the screen size.
Only the Max has more icons on the screen I think, but when USING the device …
Pictures shown - may show a bit more of what’s captured on the Max/Pro vs the mini or the 12
the size of a pic-in-pic video seems to be bigger on the 12/12 Pro/12 Pro Max but the video content doesn’t show more !
^ it’s just simply ‘bigger’ to your eyes.
Again other than more of what you see on the screen of certain content (web pages, images shown in Photos, larger spacing of text, keyboard to type on for larger hands/fingers, etc) doesn‘t change.
Honestly comparing to what’s been on Android I’m VERY surprised Android phones in low end vs big large high end from stock doesn’t actually significantly give you more to use on the screen … its just spaced out more.
A tonne of bricks vs a tonne of sugar = which weighs more?

The bricks visually and in our thoughts may seem to weigh more but the weight metric is the same. Maybe you can do more with a tonne of bricks vs sugar but that’s in the hands or eyes or minds of the end user.