We're not assuming the existence of such physical properties. We're also not assuming the inexistence of such physical properties. That's the point. You're making a leap based on no evidence. I'm making no such commitment and your arguments shouldn't convince anyone to make that leap with you. Worse, you want to use this unfounded leap to claim we know something else. It's terrible epistemology. It turns out we do know that other fact, but certainly not by following you down your unsound road.