The idea is simple.
What I would like is for the 2D software like GIMP or Krita to be able to handle 3D objects.
I think even simple low poly objects can work wonders for 2D drawings. You just create 3D objects like cylinders and boxes as drawing guides or helpers.
With this you don’t need to rotate the image in your mind. Just rotate the outlining 3D object for a new view.
Also. Like here in Blender you can layer in 3D and move or bend lines in 3D. Some A.I software could perhaps know where the line is in 3D space I would like it to be or present some suggestions. I tried to draw in 3D but the line was drawn in the wrong plane. Here machine learning could perhaps choose the right 2D plane in 3D space.