It's not just effectively identical, it's completely identical. The same matter, the same quantum state, the same consciousness.
The simplest answer would be because it doesn't ordinarily work that way.
No the fuck it isn't. Dualism is clearly true in Star Trek's universe and even if it weren't we see consciousness is maintained while beaming but is normally too brief to be perceived. (TNG: "Realm of Fear")
Beaming is no more death than sleeping, or existing for longer than a single Planck unit of time is.
Or sometimes "Ahead", in the same way Picard gets two.
So things may move pretty fast with Korby. A whirlwind rebound after things get awkward with Spock?
In essence, Discovery followed the same arc as the Star Wars sequel trilogy. They swung for the fences on doing something wild and asking difficult questions that the franchise had taken for granted; and even if the answer they arrived at was affirming, there were too many loud nerds that couldn't look past either the flaws that genuinely existed or their own shallow prejudices. Those nerds were loud enough and long enough that the studio walked it back to try to appease them and ended up with something much less interesting, which both alienated defenders of the early direction and could never appease the bad eggs whose criticisms weren't in good faith, leaving something that only a few appreciated.
Worf was a pretty crummy dad, I wouldn't be shocked to learn that as an adult he and Alexander are not in one another's lives.
And of course we know Uhura's gonna turn out just fine.
I am confused by the choice to have the Klingons look like the redesign. This is TOS era so surely they should look like TOS era Klingons, no?
Gene always said that TOS Klingons would have had ridges the whole time if they'd had the budget for more elaborate makeup. Kor, Kang, and Koloth had the redesign. There's no proof that anyone outside of a handful in that Enterprise arc ever lost their ridges-- and would you really put it past the Klingons to lethally enforce a quarantine?
Which is absurd as souls objectively exist in Star Trek and at least two major species objectively have them-- which implies most do.