What surprised me is how the equipment had labels around where to open things to rescue people, where to pour fuel, etc... It was labelled such that someone with limited (or no) exposure to the vehicle model would know what to do without referencing any sort of manual.
Very different today.
Also imo USA & the UN let Rwanda genocide happen because they were gunshy after Black Hawk Down in Mogadishu thus everyone was so reluctant to commit forces even though even limited intervention early on could have stopped hundreds of thousands of atrocities. The overreaction to Somalia paralyzed effective action anywhere else.
My position might be revisionist on that matter, but I think the Maginot line worked as planned: the goal was to force the German to go around (mostly through the Low Countries), reducing the frontage where they'd have to fight. The German did exactly that, but also pushed through the Ardennes, which the Allied planners hadn't though possible.
I have no experience in the matter but I suspect that's not it. A conscript and a recently recruited professional soldier should in theory have the same level of training. Many professional soldiers only enlist for a few years.
I reckon it's more that equipment is a lot more complicated now than in the past. And maybe something to do with literacy levels in the 1960s meaning you couldn't trust a soldier to have read and understood a manual.