Your camshaft doesn't turn the tires. There's nothing to gain or lose at the crank (or the tires) by sticking with what works at the valves. All that chain does is squish springs and drive the oil pump. That load is the same if you're making 300HP or 600HP. You've personally seen the miles and years that stock set achieved.
Now if you put 450# springs up top, fill the pan with 20W50 and jack the oil pressure up to 125#s wtih a HV pump, that's be a different story. But it woudn't be the timing chains fault for failure then. That's just be straight up abuse.