File systems have become ridiculously complex:

Some examples from my Mac:

- Backups are stored in file system snapshots, that look like folders in Finder, but are invisible when using ls on the command line.

- Applications that come with macOS in /Applications are stored in a separate partition than user installed applications.

- iCloud Drive looks like single folder in the Finder, but it's the contents of several directories merged together, with some magic to automatically download files when you try to open them. On the command line, remote files are invisible until you download them.

So I think the problem is that modern UIs try to hide where data is stored, and therefore people have a hard time learning how the file systems look under the hood.

... so they can sell them cloud.

The difference is that Windows to some degree were "file first" you go to "My Files" and from there pick a file, double click and the correct application opens. Especially Win95 pushed the "file as entry point"

That was the difference to DOS, where you'd start the program and load a file from within.

Nowadays we have circled back to phone and apps, where often you don't really deal with files anymore, but data stored in some service remote and there isn't even a save button anymore (and where it remains it is a legacy thing with a floppy icon, with the file as archaic as the floppy)