Not only that, all those magical solutions are doing is solving the easy part of development, which is laying down the widget-based layout. The actual hard part

Not only that, all those magical solutions are doing is solving the easy part of development, which is laying down the widget-based layout. The actual hard parts (different behavior based on context such as viewport size/orientation, actual UI business logic) are an afterthought. Impressive work, yet misguided in many ways in my opinion.