This. I would be willing to bet 99.9% of the human population do not have fingers long enough to operate the iphone 13 mini completely onehanded, i.e. reach all 4 corners of the screen without letting the phone slip.
The actual market for a truly one handle-able phone is enormous. It's just not possible to fit modern phone functions into a package that small though.
Who will pay flagship prices for a phone with 3 hours of battery life?