> So I built a custom app for him: a drawer that eliminates folder hierarchy and location knowledge

Fair, that is something I've observed since the introduction of iOS, where most users don't navigate folders and open files, but flip it and open an app and browse the recent files.

As for Finder itself, the column view and hit-space-to-preview is all I want for my basic needs and I miss it whenever I have to use Windows. Can't speak to other systems.