You are taking the “nothing must be done before everything has been made perfect” approach to things. It has failed spectacularly everywhere it has been tried.
What you call workarounds are things that can be done here and now to improve things. No one has claimed that they leave no room for improvement.
Trimble has started introducing gesture-based functionality to SketchUp, first via the Web versions. I don’t use touchpads or pens so I cannot say how far they have got at the moment. See