Head flow,vs. cam lift?......

this is written so cam novices have a better understanding. It is basic in the way it is written. Those of us that really understand and race cars know it is more in depth than this. Lets not get to crazy and split hairs and get super technical.

Bomber, I see kind of where your going with this from a different angle so to speak. Let me state this view point from another angle, more of a street engine stance rather than a race engine.
After reading what you wrote, and without contradicting the answers above which are correct.

It's not that the cam will wear out but the valve springs that take a beating on high lift and/or reving engines. So long as the cam is well oil feed, it'll live just fine.
A street engine that will live many many miles under all types of conditions without being serviced a lot if at all besides routine things would have a milder cam. While an increased ramp rate can be used in a street engine for many thousands of miles, the steeper the ramp, the more abuse the spring takes. The same goes with lift.

The whole valve train comes under increased scrutiny for being dead balls on accurate. Even if all is perfect, the life of the valve train is a shorter one from a race car vs the street car. The lower lift and duration ease up on spring requirements and a not so perfect valve train can survive.

Lifting the valve slower as like on the typical Chevy lobe with increase duration to meet the intended rpm operating range requires a certain valve spring pressure which is woefully weak for a fast ramp that can be used by the MoPar engines.

Power can still be certainly increased though not as much as a fast ramp cam. This is why most cam companies offer performance cams with the Chevy lobe. Longevity!

The bolt on power available from the aftermarket heads is a beautiful thing. Should you follow the same method of attack the racers in the above mentioned classes do, you should be able to find some mad power increases. But I do not think you'll like the feel of operation from the installed cam.
They tend to be a narrow rpm cam. Often nasty in idle and really crappy to drive on the street.