In my mind, QuickLook on macOS is probably the closest thing we have to document-centrism in a modern mainstream OS, with how the OS discovers QuickLook extensi

In my mind, QuickLook on macOS is probably the closest thing we have to document-centrism in a modern mainstream OS, with how the OS discovers QuickLook extensions in app bundles and uses them to make QuickLook capable of understanding more document formats. The only problem is that it’s read-only. If QuickLook extensions could provide write capabilities too, you’d have 90% of a document centric setup.