I have a lifter tick slowly getting worse in my '04 4.8L
If this question is a distraction, please feel free to ignore ...
Why not 5.3L or 6.0L?
What I'm wondering is, if aftermarket cams are better than OEM for coming apart shedding metal from the lobes or whatever it is they do?
Good question.
In my opinion, GM should be ashamed of any engine that does not make it past 200,000 miles.
That said, GM CamSHAFT failures are not common.
Lifter / pushrod / rocker / valvespring failures are far more likely.
Lifters tend to damage cams far more often than the reverse.
Personally do not know if aftermarket cams are famous for lasting as long -
but I'd not be surprised if aftermarket cams - or any other aftermarket valvetrain parts - don't last as long due to increased aggression of the camshaft profile.
Parenthetical ...
Not too long ago, Ferrari had an engine with Variable Valve Lift, where the cam profile and springs were designed so that, above a certain RpM acceleration, the camshaft and the lifter would momentarily separate from each other.