TUIs are wonderful. They are easy to grasp, fast and restrict requirements, everyone involved must think about the workflow and efficient usage. Input is focused entirely on the keyboard. Linux overs some modern TUIs e.g. installer, apt-stuff or the kernel config aside from that:

https://invisible-island.net/ncurses/ // classic

https://github.com/willmcgugan/rich // blingbling

https://github.com/dankamongmen/notcurses // hacker

For the old stuff I recommend looking close at airports, savings-banks or part-dealers. When it is influenced by mainframes you will notice likely forwards/backwards is done by F7/F8. How do you depict an plane with seats in TUI? I assume an array, 80 rows and 10 columns ;)

I'm impressed how flawless elderly co-workers work with TUIs. They read the screen, think and type and the work is done. I guess the straight workflow, clean user-interface and similarities to paper forms improve usability. I guess modal dialogs, popup warnings, status icons, right click and the modern long press are not an improvement in usability. And the many tiny icons and bars in modern text processors aren't a help either.

I think we can learn a lot more from old programmers.