Flat list of streams for followed games

There is if you have the user_read scope.
Check the API HERE

stream_type -- optional -- string -- Only shows streams from a certain type. Permitted values: all, playlist, live

The default value is live, which is what causes not all stream showing up by default

Edit: I realized I may just be mistaken here - I’m sorry I can not test this currently.
Since the other two values are “playlist” and “live”, it may just be that “all” will not show offline streams but just both of the other types. API is vague in this.