This question fascinates me. Because I don’t know that there’s any proper way to argue for or against it. It’s referring to the subjective experience of consciousness in some kind of continuum, like if we were observers watching a television screen and when we die, the TV is turned off and we’re still there just now we’re staring at nothing.

I think the problem comes from a misunderstanding of self identity. A failure to recognize that our self identity is itself a byproduct of the structure of our brains. That from the outside looking in we’re just a bunch of molecules and chemical reactions. If you were replaced by a perfect clone right now, I would be none the wiser. You wouldn’t be any the wiser either. You definitionally couldn’t be.

It’s hard to conceive of, but also not hard at all. We’re not an observer of our experiences we are our experiences. Like we are physically made up of our memories and personalities and knowledge. If your brain was copied wholesale and reconstructed somewhere else, then your experience would be that you had appeared somewhere else.