At least this would allow a transparent download your files option which is a work around for safari on both mobile and desktop, since a user can prompt to down

At least this would allow a transparent download your files option which is a work around for safari on both mobile and desktop, since a user can prompt to download files in Safari (particularly useful on mobile). However it still relies on the user knowing about this or the application having to somehow prompt it from the user, rather than transparently writing to the file system directly or mounting it as a drive. Step in the right direction for sure, still way too much hassle though. This singles to me they just made sure not to provide a first class file handing option for web developers that would potentially compete with native apps, especially on iOS