Oh well, when they get their 787-10s and a grumpy cabin crew dim all the windows during the cruise you won't be able to tell the difference.
Who knows, if we get get 4k resolution the screen will be as good as the window. With Moore's law (IT power doubles every two years) we may get there. Then again maybe not. We may need 16k resolution. I've been to a demonstration of this and it is good.
Looking at it positively, things could be better if you can't get a window seat, or are sitting over the wing or on the wrong side.