I don’t buy the idea that disintegrating my molecules and reconstructing new ones is tantamount to murder or suicide.

I definitely don't think teleportation in science fiction is meant to be killing the person using it and making a clone of them. Like unless a story is specifically about that, I don't think any given sci-fi author is trying to set up some sinister background plot where everyone is unknowingly killing themselves all the time.

But I do still have to wonder if that's how it would end up working out in real life. Sure all our cells have died and been replaced since we were born, but that typically doesn't happen with all your cells at the same time lol. imo it's probably less about cells and more about like... Consciousness or "the soul" or whatever, I don't know. Whatever it is, I accept that teleporters in fiction have some way to store and transport it, whether it's stated in the narrative or not. But in real life I have no idea how we'd be able to tell if such a thing could even work.

If all I experience is being one place one moment and another place the next, then it’s me

If I make an exact molecular copy of you and set that copy free into the world thinking it had just successfully transported, but then I take the original you that entered the transporter and lock them up in a basement somewhere, how is that any different? From the perspective of the conscious being that came out the other end their continuity is uninterrupted. They will think they are the only version of themselves to have ever existed and that they simply moved from one place to another, as opposed to being a duplicate of the original entity, and that the original entity may be dead or in this case locked in a basement.