This isn't a new idea, in fact many other users have previously voiced their interest in having the ability to play their whole music collection (including local files) on their favourite platforms.
You see; Spotify isn't just a collection of tracks, it's many people's preferred service for not only finding great music, but also getting the most out of the listening experience.
Spotify's Connect technology already allows us to listen on a vast array of devices, and encourages developers to build functionality into their products.
I love that such technology exists, it makes listening to my favourite music through my TV/AV receiver possible, but I feel that this could be improved by allowing local file streaming in addition.
Updated on 2022-09-15
Hey folks! Thanks for coming to the Spotify Idea Exchange.
We've been keeping an eye on this submission for an extended period of time, and it doesn't seem this will reach the votes necessary to put it forward for prioritization. As such, we're marking this case as closed. This includes any similar suggestions that are received.
This doesn't mean that you idea has been declined by Spotify. If we do have any new information to share, rest assured we'll check back in here with a new status.
More information about it can be found here.
Thanks for your understanding.