I also had this worry when moving from an iPhone 8 (or something) to a 14. But you can use a swipe down gesture on the white bar at the bottom of the screen wh

I also had this worry when moving from an iPhone 8 (or something) to a 14. But you can use a swipe down gesture on the white bar at the bottom of the screen which pulls the whole thing down, bringing the top part of the screen easily in reach of your thumb. I use my phone one handed very often.