Imagine you had a Sufficiently Large Budget to create the software you've always imagined. There are still hard problems, you can't just wish a revolutionary new operating system into existence of solve NP hard problems, but you don't have to worry about the budget.
What do you create?
(As a bonus question, what software would benefit humanity as a whole the most if it suddenly sprang into existence)
Furthermore, it should also let you assign metadata like materials to objects so that you can do accurate physics simulations. For example, if I make an object and set its material type to "spring_steel" I could then run a physics simulation where I get to see how much force is required to make it bend (e.g. while being inserted into something else). It would also be nice if you could just manually set the flexural modulus, fatigue index, etc to any given material for the same purpose.
Any manipulation via the GUI would automatically update the script/code and vice versa. It would be the ultimate parametric CAD tool.