IMO arch or similar is going to do more towards teaching Linux than raspian will. Just install that on a cheap laptop/phone and play around with different apps/configs.

For hardware learning pis arent even that great, an stm32, Arduino , or esp32 is a fraction of the cost(so you don't have to worry about burning the io pins out as much) and the toolchain is basically the same(simpler I'd argue even)

You can use arch on raspberry pi too. https://itsfoss.com/install-arch-raspberry-pi/

But not sure I agree that arch is the best linux distro to start with for someone new to computers that grew up on an Ipad.