I don’t think I can defend my position very cogently or I’d argue against other interpretations more vigorously - and as I’ve said I’d love to be wrong. It’s certainly at or beyond the depth of my understanding of consciousness, but that doesn’t mean I accept that yours is necessarily more valid. (no snark intended with that comment)
When I bring it up I get challenged to articulate why I feel that way and inevitably get presented with a question like yours that I can’t answer - but generally no one gives me a “here’s why you are wrong” argument, they just give me “you can’t differentiate between what you’ve posited and a nondestructive consciousness transfer and therefore you are wrong.” I maintain that my lack of ability to articulate that difference reflects poorly on me, but doesn’t actually prove I’m wrong.
For example, I don’t think my inability to articulate a ‘property that is altered’ represents a weakness in my position, and I’m not sure a property needs to be altered for my understanding to be true.
Using (very poorly and atypically) the ship of Theseus example, I think we’d agree that if I had two absolutely identical sets of shipbuilding materials, down to the atomic level, or further, down to the state of all observable properties of that matter and the particles that make it up, (I have no idea how one would achieve such a thing), and built a ship from one set of those materials, then vaporized that ship and built another that was 100% identical using the second set of those materials, those ships would be two identical but distnict entities. I don’t think I’ve seen an argument that convinces me that the same wouldn’t be true for pulling my consciousness (ephemeral and subjective as it may be) and body through a transporter or other such destructive process.
Your argument feels like you are telling me that if I use a replicator to make two different but identical cups of earl grey hot they are actually the same cup of tea, when plainly they are not. Considering (sticking with star trek) the stories of duplicates due to being stuck in the “pattern buffer” or similar handwavium, it seems clear that the ST transporter is capable of creating multiple entities. The only difference between a normal transporter experience and one of those freaky transporter accidents seems to be whether the two entities are both alive at the same time.
COULD there be (since we’re in the realm of scifi anyway) some method of transferring consciousness that wouldn’t seem like death to me? Yes I’m sure there could. But I don’t think I’ve seen one in any popular scifi, at least not that I can think of right now.