> All I want to do is play the same shit on ALL MY SPEAKERS. My living-room ones, my patio ones, and my backyard ones. All I need is A, B, and C speaker switches. But NOPE. As far as I can tell, nobody makes this. Nobody addresses the 99% use case for multiple "zones." There are at least NINE AMPS in my receiver, but I can't play the same source on three pairs of speakers.
Maybe a smart speaker switch like an Audioflow[0] is up your alley?