The Gen 4 is a wonderful looking vehicle with a lovely cabin for the money. When the first one was out, I sat in one at the dealer and it made my vehicle seem like it was from the 1980s.
However, it seems to have been constructed with all the bells and whistles in mind. Because you had windows in the Gen 2, you don't need a back camera or a blind spot monitor, but as wonderful as the Gen 4 is, it was obviously created with visibility at the bottom of the priority list.
While it's comforting to imagine that a good driver doesn't require these items, many current automobiles make being a decent driver difficult without blind spot monitoring and other features.
Even on the C3, which is not as low-roofed as the Mazda 3 but does have kicked-up rear windows, a sloping roof, hefty C pillars, a tiny back window, and dark tinted rear glass, a reversing camera is a much better alternative than looking out. Yes, you still look over your shoulder, but your range of vision is almost nonexistent.