That last one is practically impossible for any but the most simple of applications. It is much easier to reuse a (graphical) UI between desktop and mobile than

That last one is practically impossible for any but the most simple of applications. It is much easier to reuse a (graphical) UI between desktop and mobile than it is to reuse a GUI with a TUI. TUIs have core differences, from using character cells for positioning and only allowing characters for presenting the UI (i ignore stuff like sixel and regis since those aren't supported by most terminals), to only having a very small selection for colors (again ignoring things like terminals with 256 color support) and a very limited input (often special keys do not work, mouse may or may not work, etc). These things affect greatly the type of UIs you see in terminals - which is also why even today you rarely see terminal applications use the richer UIs that you could find in text based DOS applications in late 80s and early 90s. But as far for the rest, FWIW, everything you describe seems to be a thing in Blender's UI (including the ability to right click on every actionable element and see what Python function it calls), which probably is kinda expected considering that it was built around Python. Sadly the Blender UI is not something you can use outside of Blender since it is tightly coupled with the rest of the application. There are some attempts to recreate it as a reusable library (e.g. Blendish), but they only go as far as to recreate the look.