I like the idea of having pure functions f(state)=view, however, wouldnt this be very slow for very big ui applications? Also the only reason todo this on web is to use some sort of double-buffering and prevent redraws before everything is updated. On mobile native you have control over these things. But thinking about it, doing purely functional UI for native apps would never work, right? You need todo a dif each and every time the ui updates. And this happens a lot for example for sliders, or animations.

Is the approach inherently flawed for fast UI applications?