I love Android but Android does that too. Apps have their internal storage area which you can't access unfortunately (not without root anyway). Nor system files.
> There was almost a whole decade there where Apple pretended that the feature just didn't need to exist.
edit: oh, I think I get it. My original post wasn't intended to be read "iOS invented the file explorer, has Android also a file explorer app" (which would be silly, of course) but "when Files app released, the AOSP file explorer that commonly ships as the default was lacking, has this improved (caught up to Files app)"
Android is possibility/ (overdose of) options Apple is polished (and late).
Different strokes for different folks
You are correct that each app can only see a specific part of the filesystem, unless the apps are by the same developer and part of an App Group.