[ 11/9/20 ]
Because reality seems to be sufficiently complex that the old stories we have about it will be forever being revised as we gather new levels of understanding about it.
And in some circumstances, the old stories will still work as well as they ever did. For example, a carpenter still treats the earth as being flat, because that is close enough for their purposes. At the scale of measuring lumber to make a house, the difference between flat earth and round earth is below the level of error in the instruments carpenters use.
Flat earth has never worked for sailors traveling long distances, they have always had to deal with the earth being round, if they wanted to get someplace then get back home again.
If we want the benefits of things like medicine, then we need to understand how cells and bodies actually work, and that requires learning something about evolutionary genetics. And as someone who started studying that 50 years ago, it seems very likely to me that should I live the rest of eternity I will still be learning interesting things about it, we do in fact seem to be that complex, when you look seriously at the details.
If we want technology like these computers and the internet, then at least some people need to understand something about quantum mechanics, and its eternal uncertainties (as things like transistors are built from such understandings).
If all you want to do is live in a house of lumber and tend some animals on a farm, then you don’t really need to worry much about such things; because the old ways are still useful in that sort of context; but the new ways are actually even more useful, but they take a lot longer to learn.