Some science fiction ideas are based on making a copy of a person, like “uploading” them into cyber heaven or teleporting them by breaking them down into molecules and reconstructing a copy.
If you subject yourself to one of these machines, you will end. Your subjective timeline will end. It’s death, basically.
There might be one or more copies of you but it won’t be you waking up inside that copy. That copy believes it’s you. That copy wakes up and is like “Oh, awesome, this li’l teleport went nicely”. Remembers that time in second grade when you had a nosebleed and were allowed to leave class early or whatever. Good for it. But you’ll be gone.
And no-one will ever know because when they ask your copy about it, it’ll be all like “yeah it’s great, maybe somethings are a li’l fuzzy but I’m basically fine” and everyone will be like “see, it actually is you that move over” because that’s what your copy believes you did.
And they can make more than copy if they can make one, put them in slave factories or meat grinders or whatever.
The copies will have lots of fun. Good for them.
What I’m trying to convey is that my subjective timeline will end. Same if you get a cousin or sibling or child, that’s great and awesome but you yourself can’t feel or hear what they feel and hear. Getting a copy is like getting a clone or a friend or an enemy.
The Answer is especially relevant here since the copy can be called “you” but the signified you beyond semiotics, that would end.
Now in the larger dharma there isn’t even any “I” in the first place, we’re all one, and that’s great. But with that definition there’s no need to even send a copy. If I wanna go to Mars they can just slap a “Hi, I’m Sandra” name tag on some martian and call it a day. That has as much or as little bearing on my own subjective ability to experience Mars as a transporter copy would have, i.e. zilch.