A lot of students use phones and chromeOS, both of which obfuscate file system. Remember majority of gen z are still in college or school.
And even after you graduate - how many job’s actually require you to interact with the FS? In my company for example people are supplied with a laptop with everything already pre-installed. Majority of folks would just use couple of the apps they need for their job and a web browser. As for files - they just have an endless list of stuff in their downloads and desktop folders.
LLMs are pretty novel. They are made possible by invention of the Transformer model, that operates significantly different compared to, say, RNN.