I think the main problem with UI is the movement towards scalable graphics fitting all types of displays which unfortunately can't be as complex as raster graph

I think the main problem with UI is the movement towards scalable graphics fitting all types of displays which unfortunately can't be as complex as raster graphics with the same size constraints. Hence flatness and overly abstract, "simple-gradiented" shapes everywhere. I think once people realize that 8K will be the final resolution of displays, raster will come back as the number of display formats that need to be supported will be limited and graphics could be rescaled on the go. For now we have to suffer through the "modernism" phase of UI design which like in art makes only around 5% of people inspired, rest is underwhelmed; or stick to the last bearable OSes like Win 7, Mavericks, iOS6...