None of those techniques look generic though; you could write pipelines in games that worked like this. But you can't (easily) drop it into an arbitrary game.

And while you're right that the computation on the client end could be made lower (depending on the constraints of the game), you're now going to need to care about the hardware of the client beyond "can render a video stream". My (regretfully) smart TV has trouble rendering its own menus, it's not lifting a finger to do a game.