The developer builds a beautiful interface for searching, curating, and organizing media in a given genre. Everything down to the moment of streaming works as you'd expect, at which point some boring public domain content is looped for the given duration of that stream.
Users would get the benefit of having the curated data accessible through the GUI-- e.g., you could search all the Tom & Jerry cartoons, get/sort by metadata, etc. Perhaps even view a screenshot (not sure about Copyright law around that).
Fringe benefit is that this creates a reference UI against all the streaming services may be judged, and gives new users some idea of what it was like to search and use "completist" services like what.cd, etc. Not to mention how thinking about the potential existence of such services can change the options we think we have for how to spend our time-- compare writing a blog in 2021 complaining about a commercial streaming service's faults vs. "completing" some private tracker's Tom and Jerry offerings with the missing cartoons from your own collection.