Transporters work by de-assembling something (e.g. you) and re-assembling it somewhere else. What if, when you're dis-assembled, you die, and the re-assembled version of you is essentially a copy? Then every time someone steps onto a transporter, their final thought before death is that they'll end up beamed somewhere else. And the re-assembled version (copy) just thinks that everything went fine and continues on like nothing bad happened.
I don’t think that’s quite the same. Sleeping (or intoxication) is a temporary effect clouding your “normal” consciousness. Once whatever caused it goes away - assuming nothing actually changed, as you say - you’re back to your old self. While sleep is “discontinuity of consciousness” in one way, a tell is that you can still remember dreams. If you’ve ever had (deep) general anesthesia, that time you were under can seem like it’s “missing” in a way that pure sleep doesn’t.
In contrast, the teleporter sort of… obliterates you, shredding you into atoms and rebuilding you later (if the matter doesn’t need to “travel”, at least the information is limited to light speed). It’d be no different from any other catastrophic damage to the brain.
The determining question for whether or not it’s the same is this: Are you the physical matter of your brain, or the electricity running through it? In the first case, sleep isn’t death. In the second case, it is. I would argue that you’re closer to the electricity than the brain matter, since an unpowered brain is how we define death.
But REALLY it ultimately doesn’t matter, if you think about it. An exact clone of you created after any kind of destruction of consciousness is no different than the original you had the destruction never occurred. We just intuitively really do not like that idea.
Or, since we’re getting philosophical anyway, are you some sort of spiritual entity inhabiting your body and experiencing the physical world through it?
BTW - if that’s the case then the transporter in the original question is definitely a death machine.