Drawing where to put the widgets (and not using constraints or grids or automatic layout or adaptive rules or responsive design, or user testing and performance measurement and empirical evaluation) isn't the hard or important part of user interface design.
Who is supposed to benefit from this? A company who refuses to hire a competent user interface designer and wants to crank something out really quick regardless of quality? Users spend much more time using an interface than you spend designing and implementing it, so optimizing the time and amount of mental effort you have to put into making a user interface isn't worth it if it doesn't result in a better, easier to use interface.
We are already there with Framer X and competitors pending launch in the near future. There is a learning curve that most designers are not super comfortable with yet, but I expect that will improve quickly. We also are limited currently to React for Framer X but I think opening it up to other front-end frameworks is on the horizon. Exciting times!