Why does the cockpit have windows, is it a structural design burden?
Yeah, it may be better. But what happens if the camera gets dirt (as everything else does in a flight) or if the camera fails for whatever reason? If the aircraft suffered an electrical malfunction and the camera was to turn off? Also, this is way more expensive than just fitting the window. The technology would also increase the weight of the aircraft. It's a good idea that I am sure that aircraft manufacturers have contemplated. It is just too impractical.