Historically hasn't this always been the case? I thought it wasn't until recently when college became a at least remotely affordable option.
This democratization was controversial at the time, though it also coincided with the biggest boom in global wealth the world has ever seen. I suspect this is more correlative than causal, and is tied to the increasing energy available to world economies through fossil fuels. That said, technological increases supported in part by broader education have increased productivity ($GPD/GWh) as well.