Instead of a piece of silvered glass which requires no power input and always works? K.I.S.S.

Keep in mind that you lose some of your ability to judge the distance with camera/screen setup due to no depth perception. There are no 3D camera+display setups that I'm aware of yet.

I understand they are in Europe, but in the US regulators demand the simple always works mirrors. This is of course subject to change as different pros/cons become known.

No, at least not in the US. It doesn't matter if cameras are better and safer, the US regulators won't allow it for decades if ever.