I have to respectfully disagree. Air travel is statistically safer than ever before and catastrophic failures rarer than ever before.
When I first flew the B747-400 I recall flying with a senior captain who had previously flown the B747 Classic right from its introduction into British Airways. He had suffered 13 engine failures on early aircraft. He had a flight engineer and each event was handled safely.
I flew the '400 for 10 years and suffered 1 engine failure which was a failure of the FADEC we handled it safely. I think I prefer more complex but ultimately more reliable modern engineering.
There will always be human error no matter how we strive for an accident free environment. I cannot agree that less sophisticated engineering warranting a third crew member would ultimately improve safety.