I can't remember exactly what the "potentially life threatening" shock hazard was generally considered to be, but it was somewhere in the 40V range. That is one good reason that things like "low voltage" lights and such exist. Far less risk of electrocution and fire hazard.
The downside to using low voltage is that running high wattage devices is simply impractical. It's specifically why you can't buy a little "electric furnace" to heat the interior of your car in the winter, while a 1500 watt home device (1500 / 110 = 13.64 amps) can easily do that and is very small, attempting to pull 1500 watts off of 12V (1500 / 12 = 125 amps) would require wire thicker than a good set of jumper cables.
Where I work at, we use "professional" camera's in a CCTV system. Output power is 24V AC which the camera will convert down to 12V DC. Advantage to this is that the 24V AC won't droop in voltage over distance like DC would and with the down convert at the camera, the wires are thinner than a 12V system would be. A manufacturer that keeps the benefits of "proper" power design in mind when creating any device gets a lot of benefits for doing so, even if the parts require custom manufacturing compared to more easily available "off the shelf" part designs.