Comment by JdeBP

If you had been born in the 1960s, you might well have learned by dint of being alive at the time that the world underneath /usr was pretty complicated in the 1970s, 1980s, and 1990s; that /etc was where some of the things that were used to boot the system once went; and that the tale of sbin is complex and slightly sad.

The tale that things were simple until they went to pot in 2000 is wholly ahistoric.