This appears to be aiming at mobile, so maybe a split screen wouldn't work, but I'd at least argue that directories should be at the top. There are cases where

This appears to be aiming at mobile, so maybe a split screen wouldn't work, but I'd at least argue that directories should be at the top. There are cases where a file is associated with directory, e.g. you export a web page and its contents are saved within a dedicated directory, and some languages will allow module.foo and module/submodules. But those are odd cases and the insight that the file managers had was that folder navigation and file manipulation are two separate things. If you need to move a file, you always want to move it to another folder. All the files just get in the way. If you want to find a file, it's in a folder, it's not "between" two files. Putting everything together is plainly nuts.