Those electric suns really did not convince me at all. I do not know if your linked product uses a new technology, but the ones I tried, I disliked and they could never replace the real sunlight for me.

And yes, I also meant the space problem. Open space underground might solve it for some people, but probably not for me. I would always feel like in a prison, if I cannot go outside and feel real wind. But humans are adoptable. Still, I suspect quite many, who think they want that, would probably go crazy, if they really would be stuck in a bunker forever.