The "Pittsburgh Persimmon" Taylor Made driver didn't offer much of an advantage aside from durability. The real change in drivers came 10+ years later with the Great Big Bertha ($499 then!) and later, the iterations of other drivers like the 975D and one year, J's Professional Weapon.
Those drivers were all smaller than 460cc, so when they introduced larger drivers with maximum COR...with a ball like the ProV1, the cow went out of the barn.
I'm not arguing that the metal driver broke the game in '79. I'm arguing that the
change that broke the game was detaching the relationship between size, weight, strength, and density of drivers (and later most clubs). Previous to the metal driver, the larger you driver head was, the heavier it was. You could shift the center of mass down, but you couldn't increase the size of the sweet spot simply because you had uniform, horizontal density.
That this insight and its implications were not realized for a decade, to me, isn't important. We broke the game when we removed the self balancing relationship between size, strength, and weight when we remove the need to have club heads of effectively uniform density.
You're free to disagree, and I think that there is a non-trivial amount of shaft technology that has increased the distance as well, but my point stands. I think the ProV1's main benefit was simply removing the tradeoff that the previous generations of hollow drivers created, which I think was significantly less relevant to the era of wooden clubs, which already prioritize (or at least balanced) control over power.