I'm and "old foggy" but even I now trust cameras more than my rear view window.
![Stick Out Tongue :p :p](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
Use of both are good, but rear cameras are getting to the point that they have better coverage than physically turning. We'll see with the M3 but I expect the side view + shoulder check will cover anything the rear camera doesn't?
Unless you mean for cars that don't have that, then yes.
P.S. I actually run my Bolt rear view mirror nearly all the time in camera mode. The only time I don't is at highway speeds when it's wet enough that the lenses gets dirty.