I know there have been requests for managing metadata locally. There’s a thread on modifying files which, I agree, isn’t the way to do it.
But has there been a reason why there isn’t a file format that can hold the data for media, particularly video? A YAML file in a directory would be all that is necessary, I would think.
With TVDB making questionable life choices, a universal file format that all the media players could use would seem prudent now.