It's literally like this:
Materialists/Physicalists: "The thoughts in your head come from your conditions and are ultimately the result of your organs and nervous system. Your consciousness is linked to your brain activity and other parts of your body interacting with the physical real world."
Dualists: "Ok but what if there were an imaginary zombie that has the same organs and molecular structure as a living person but somehow isn't alive on some metaphysical level. If this zombie is conceivable, that means it must be metaphysically true somehow."
Materialists: "That's circular and imaginary, isn't it?"
Other dualists: "Ok but what if I were in a swamp and lightning strikes a tree and magically creates a copy of me but it's not actually me because it doesn't have my soul."
Am I reading this stuff wrong or are these actually the best arguments for mind-body dualism
the point of those thought experiments is to illustrate that the experiential components of a living beings existence (known to philosophy nerds as Qualia) are not necessary to explain the biological/physical phenomenon of life. a computer can process information too but it doesnt experience it as far as we can tell. even phenomenon like the weather can be considered an information processing system but we don't typically attribute consciousness or internal experience to it. hypothetically you could therefore have had humans or other life that behave in all the same ways and do the same information processing tasks but without an internal experience of their existence, and the fact that we dont have that but we have us instead may mean consciousness is more than just information processing or illusion. its not strictly an argument for dualism, but as part of the discourse against a physicalist materialist conception of consciousness as illusion, or information processing. personally i think consciousness is somehow fundamental to existence in ways we dont understand, like space, time, or matter, and even phenomena from subatomic particles to stars might have an incomprehensible-to-humans internal experience of some kind.