I think the main benefit would be how much it would simplify software. Software that wants to do something useful with user-downloaded content doesn't have very

I think the main benefit would be how much it would simplify software. Software that wants to do something useful with user-downloaded content doesn't have very good options. To do more than just display a list of files, and maybe try to render a preview based on the file extension, software has to implement support for reading lots of different kinds of files and parsing lots of different kinds of metadata in those files. (MP3, MKV, PNG, JPG, OGG, etc). And then, because the data contained in that metadata is only semi-structured, and varies between content types, it has to do a lot of error-prone heuristics to do anything useful with that metadata. Like, for example, figure out that these files are the tracks of an album, and this file is the cover art. This is definitely possible! But it's very hard, and even then has a long tail of issues. If a publisher or packager could add structured metadata with a constant format and filename to a release, then all the downstream software and services could mechanically consume that one source of metadata, which would simplify everything enormously.