Raising a child to use computers via command line is very interesting.
I would want my child to be tech-savvy, but most parents I see make the mistake of just giving their kids an iPad. I think it's very destructive to their attention span.
On the other hand, having a cheap laptop with only access to TUIs could be used for improving reading skills and tech literacy. Add some TUI games like the good ol' days of BASIC, and it can be just as entertaining as an iPad.
If iPad had ability to act like a screen for RPI that would awesome - portable, battery powered, versatile, etc.
what do you actually want to do? I have https://github.com/coder/code-server and https://jupyter.org/hub running on a PI, along with tailscale on the ipad and pi. This allows the IPAD to have a full editor, and a shell onto the pi.