There is a nice guide here: https://konradybcio.pl/linuxona7/. This is how to get Linux installed on an iPhone. This does not seem to be fully working, but this is only a matter of time until we get the kernel modules working that are required for the OS to work properly on the iPhone hardware. This could be an interesting hacking task, getting Linux running natively on the Apple mobile telephone. Maybe they could get Open BSD running as well. That would be amazing. All you would need is some kind of keyboard for it. I wonder if it would be possible to have an onscreen keyboard when using the Virtual Terminal interface? I guess it could be hacked in somehow. There is also a hack to get Linux running on an older iPad. https://twitter.com/quaack723/status/1531965090018349057. That is also very interesting. These are early days for such hacking, eventually, there will be a version of the Linux kernel with proper kernel modules that will work fine on the Apple hardware. I wonder if Apple would be upset that people are doing this. But I guess not. You still need to buy the hardware, you just need to remove the current iOS and install Linux.
I love hearing about hacks like this. This is amazing, this would be better than the current iOS. It only just got WebM support in Safari. That is very slow. Firefox would be better than Safari any day. But hardware hacking like this is fun to do. And it is good the spirit of hacker culture is still alive in 2022.