I’m very upset that iOS doesn’t support using a phone as a jump box.

You say this matter of factly and yet I've seen countless people talk about using termux more than a desktop shell.

Maybe iPhone is different but most phones you can connect a keyboard to, making the shell pretty usable. Not my cup of tea but I have tried it. I'm still holding out on the dream that a good Linux phone might exist one day.

A shell is perfectly useful on a touchscreen device.

> a 50 year old computing model onto a phone

What? Do you think command lines are based on the lambda calculus or something?