I feel that way too. I stopped being invested in Blizzard’s official story in BfA, but still saw Azeroth as a fertile ground for RP. Then SL killed my remaining interest in one of my favorite fantasy settings that I grew up with.
As for the cinematic? Even if we charitably assume that this was Danuser’s intended direction for Sylvanas’s story since at least Teldrassil, it means he massively blundered the execution. More likely, though, it’s his way of trying to write himself out of the very small corner he wrote himself into by retconning character motivations and then retconning the retcons.
By themselves, the “fractured soul” and “it wasn’t really me” storytelling devices are valid. Since The Order of the Stick was mentioned in this thread, let’s remember its more recent story arc…
Massive OOTS spoilers
We know from the start that Vampire Durkon is of Evil alignment, but then for the remainder of the Empire of Blood arc, the story tricks us into believing it’s still him. We saw him reconnect with the Order and try to work with his vampire condition being a hindrance to his team…
And then the story dropped the revelation that he was not Durkon at all, but rather an ex nihilo spirit occupying his body and impersonating the real Durkon and holding his soul prisoner, helpless to act. Most importantly, this was revealed to us (but not to the Order) before the vampire committed any atrocities. We saw the tragedy of the Order not seeing through the ruse before it was too late; and after that, his actions towards Hel’s plan fueled our desire to see the vampire destroyed and Durkon’s soul freed.
I mean, Hel wasn’t a particularly deeper villain than the Jailer. She wasn’t quite on the level of Redcloak, Tarquin or Malack. But that was fine because the story wasn’t about her — it was a story about Durkon, his introspection, and finding his agency, told through the lens of a stranger, the vampire, sifting through Durkon’s memories and inadvertently helping him find the agency he was lacking all his life — and thus causing the vampire’s undoing.
Now imagine what a hollow story it would have been if for the whole arc, the revelation that the vampire wasn’t Durkon was withheld from us, if we never saw these dialogues inside Durkon’s mind, and were puzzled just why our pious dwarf cleric of Thor was willingly going with Hel’s plan — and then only after the vampire was destroyed, we’d see the “haha, it wasn’t him” revelation and maybe saw some of those conversations, but only as a flashback.
Bottom line is: if you want to do an “alien soul driving the body” story, fine. But tell it right from the start, rather than in a way that feels like a cheap cop-out.