Why are user interfaces still designed one by one? That's like redesigning the wheel or a chair each time we want to make a new one.
I envision using mechanical optimization techniques like I would use to design a bridge applied to user interface and interaction design. We need to collect data on user interaction patterns and then use this data set as the boundary conditions of an optimization design space.
If we have devices who know who we are apps can be scaled for button layout and responsiveness. Then our apps will scale their design if we are young or old. Specific user needs can be addressed on a user by user basis.