I dont know what to say. I relate a personal experience. Yours was different. Good for you.
My problem was not using apps, but the other stuff. I did as I was used to, stubbornly bumbling around, feeling sure I would run into the solution. But I never did. I had to look up instructions, several times. That was never necessary with my old iPhone.
Except for the fact that you can’t scrub on the native video player by swiping anywhere, you now have to use the time-bar. Drives me nuts.