I dunno if the Automotive Manufacturers "Saw it coming" or precipitated it through cost cutting in manufacture . . It was about in the mid '70's that we started seeing cams "Go Flat' on both SBC and BBC engines with aftermarket cams in them. I shared a building with a Racing Engine Builder back then and he started seeing camshaft failures about that time. Cop Camps were the worst back then, and if you wanted to be bulletproof you shelled out for a Crower Valve train. Their selling point was that they hardened all rotating surfaces, but they too suffered quite a few failures.
And here's one of the basic reasons why . . Metals of the same hardness don't like each other. If you have a Kryptonite Cam Lobe and a Kryptonite Lifter surface, be it flat tappet or roller, one will "Gall" the other the first time the Lubricant fails or isn't there . .
That's why all your rotating bearings are made of a dissimilar metal, much softer and malleable. While the Bearing metal isn't actually self lubricating, it takes up the slack for a whole plethora of things like dirt, lack of lubricating film at one time or another and heat caused expansion and contraction. Like metals can't/won't do that.
And stupidly, two similar metals with the same hardness, generally, when rotating together at high speeds and heavy spring pressure or other resistance will gall almost immediately without some sort of "Bearing material(s)" being present between the two. Basically, the Zinc and other bi-metallic additives become the "Different metal" that keeps the two similar metals apart.
The above is an attempt to explain why the aftermarket parts manufacturers have gone to less hardening of their Cams and some other rotating parts that comprise an assembly. If you have hardened roller or flat tappet followers (Lifters) then you shouldn't need a hardened cam lobe to make it work, and thus, if you want to be correct and safe, you'll put the engine together with lots of Assembly lube and run high contents of Zinc and other bi-metallic additives to your oil, or buy high buck oil with all that already in it . .
In theory, this avenue cut manufacturing costs and gave the racers a better product, if they followed the instructions( Instructions? I don't need no stinkin instructions) and understood why they were doing it . .
They forgot who they were dealing with . . Heheheheheheh . .