It only works because the educators are complicit. Most bachelors degree textbooks in basic sciences do not need to change from one decade to the next. My Lorrain and Corson Electromagnetic Fields and Waves from when I was studying applied physics in 1975 is just as correct now as it was then.
I don't disagree about the complicity. However, biology and statistics, even at intro level, have had significant updates in material covered over the last 10-20 years.
More subtly, terminology changes. My copy of Rudin's Principles of Mathematical Analysis is just as correct now as it was when it was published in 1976, but I remember one of my professors describing the terminology as somewhat dated, as of the late 2000s.
