An idea that anyone is free to take: JSON-definable UI for command-line apps. Define checkboxes for flags, inputs for arguments, buttons for commands and file pickers / droppable wells for file input. Allow some customization of layout of these elements. Have in-app "store" to download these JSON definitions, maybe even suggest them based on `which` output. Electron app, obviously.
You have to define the behavour of your UI elements as well as their placement, at which point you're writing a program. The best language to write a program in is a Turing-complete programming language specially designed for that task, not some cobbled together UI-definition language with ad hoc add-ons to processing.
Like it or not, the whole low code movement is about this.