It isn't so much that there aren't valuable things to learn, it is that there is so much to learn that we don't have any good ways to prioritize them. We don't know what the future of cognitive enhancement will be or genetic manipulation. We don't know if there will be a language revolution in the future or ways to take in information faster than through visually.
We don't know what the prospects are for economic growth. If there is 2 percent growth for 70 years, today's standard of living could be produced in 25% of the time. We are only a couple hundred years into the industrial revolution and around 70 into the information revolution.
We don't know whether the future means catastrophe or untold riches. What book can prepare someone for that? So, we just pretty much teach kids the way we have for the last 150 years with a tweak here or there. It is just habit. Nothing else.