Would you consider a 3 point seat belt superior to a zero point? I believe that’s the question.While I consider a 5-point harness superior in safety to a 3-point seat belt, I haven't installed it in my cars and would not recommend to make it mandatory for commercial drivers.
The safety or mitigation should at least be equal to the amount or risk someone is willing to tolerate.
Shooting personal photos? 1 card, no problem for me.
Shooting portraits and events? 2 card, great!
Shooting a large scale commercial job? 2 cards, on-site backup, great! Add off site backup, even better.
Convenience and environment will also dictate the standard operating procedures, just as you would expect in car safety. More risk, more safety.