It'd be a sadder world if modern audiences could no longer enjoy Homer, or Shakespeare, or P.G. Wodehouse, or Firefly. It'd be a poorer world if current art could no longer build on or remix older art. Does this really need an argument?
Good art can and often does contain topical references which are mostly ephemeral, but I can't think of anything I've ever seen which was both a) entirely ephemeral and b) worth a damn.
Fair point, although this example is ephemeral by necessity rather than by design. If you could experience those shows again whenever you felt like it, maybe via some improved VR setup, and share them with your friends/kids/postman, wouldn't that be strictly better?
Good art can and often does contain topical references which are mostly ephemeral, but I can't think of anything I've ever seen which was both a) entirely ephemeral and b) worth a damn.