Terminals are text. Text adds features missing from gui namely:
* Ad Hoc
requirements change and terminal gives ultimate empty workbench flexibility. awesome for tasks you never new you had until that moment.
* Precision
run precisely what you want, when you want it. you are not constrained by gui UX limits.
* Pipeline
cat file.txt | perl/awk/sed/jq | tee output.result
* Equal Status
everything is text so you can combine clipboard, files, netcat output, curl output and then you can transform (above) and save. whatever you like in whatever form you like, named whatever you like.
Unix is not about a terminal, that the obsolete medium, kinda like preaching about DOS PC with 386's... and CGA video cards.
9front copes with actual text throwing the terminal as a different tool to run legacy stuff in such as SSH or some small ANSI C tools either with the APE compat layer or NPE binding ANSI C code to Plan9 native functins.
You can resize windows with shells under 9front freely, no more SIGWINCH. No more broken cuts and pastes while running a terminal multiplexer. No control code risks executing potential malware.
Sure, I get the theory, so why doesn't exist? Where's my modern text/command based interface?
In 9front, a decades old fork of Plan9. It's basically more Unix than Unix itself, by expanding the 'everything it's a file motto' and now for real and leaving out useless VT220 emulators (and any TTY/serial emulating connections) for legacy stuff such as the 'vt' emulator itself running under a graphical window and, for instance, when running SSH against Unix machines sending you a PTY plus a shell.