[ratel]

I think it is an interesting idea that needs some further exploration.

I do see some problems with it that were not addressed. The way the demos are setup are by definition an NP!=P problem. It is easy to verify you found the right command, but may be fiendishly difficult to navigate the tree to get there. Menus with sub-menus having sub-menus at least makes it visually clear which paths you have not taken and allow retracing your steps. Something akin to Ctrl-R in shells may be needed to allow you to type certain keywords to find all possible actions.

Options and parameters are not part of a decision tree as they don't specify a logical action that will follow, they just change the action. Those parameters need evaluating the entire progress in the tree to be able to suggest a next available parameter, option and action. Try it with something like ffmpeg. Modelling this to work in a CLUI will evolve into a hard problem very quickly.

The more actions, options, parameters I add as a user the more important it becomes that I can backtrack and correct mistakes. Corrections may or may not have consequences for the position in the tree I already choose. Starting over even from there might not be the right solution in terms of usability if the correction does not necessitate it.