I'd be interested in a non-gamified CLI-builder GUI in this style; it'd be especially cool to surface flags from man pages. Many CLIs follow conventions or are easy to remember for basic use cases, but as soon as one is juggling a dozen flags and multiple pipes (ffmpeg comes to mind), it can be a tedious workflow to do it all from a terminal.
I usually resort to making a bash script with a bunch of intermediate files at each step so I can see what’s happening.
Here’s a tool I’ve seen around but never had a big need for: https://github.com/akavel/up