Absolutely no hard fact here, but empirical evidence would indicate that the cams aren't being made of the same materials or surface hardened as well as they used to be.
I'm saying that because for years, 99% of us ran plain old Valvoline or Pennz racing oil that had little or no additive and while we suffered lots of bearing loss, seldom did we hurt a camshaft, and when we did it was usually an errant rod or broken lifter that did the damage, not a flat lobe . .