I just finished Mask of the Betrayer and it felt pretty much like an inferior clone of POE2.
Thematically wise also.
I am not even sorry.
Can you tell us why?
Yes.
But tomorrow, when I'm sober.
Okay, while you're doing that, let me lay out some major differences between the two games.
MOTB:
~You wake up not knowing what's happened.
~You find out that you've become a spirit eater, cursed to consume fey and elemental souls in order to survive.
~You find out that an ancient spirit, Akachi the Betrayer, now resides in you and that he carried the spirit eater's curse with him.
~You find out that some old lady was once Akachi's lover, and she put Akachi's soul in you to potentially end the curse.
~You learn that your own soul is actually trapped in the Wall of the Faithless, so you travel to the land of the dead.
The endings depend on what you choose. It's true that you can't possibly destroy the Wall of the Faithless, but it actually makes sense here. The Lawful Neutral God of Death is not just going to let you destroy the status quo that has worked for centuries. And what good reasons do you have for requesting this? You only heard about the Wall of the Faithless like 20 minutes before the end! You're just a guy trying to get rid of an ancient cursed spirit and get your soul back. This game plays out like a detective story, and the main focus is not about the Wall of the Faithless...at all.
POE2:
~You wake up and Bereth immediately blackmails you into finding out what Eothas is up to.
~You track down Eothas and find out that he's going to destroy the Wheel and potentially get every soul trapped in the In-Between.
~The Gods order you to stop Eothas.
~You get to the end. Eothas curiously asks you a couple questions. He says, "cool story, bro" and then proceeds to destroy the Wheel anyway.
The story here is clearly more focused on the fate of the world and stopping Eothas at all costs. In fact, throughout the game, they beat you over the head with it. Getting your soul back seems like a side project because at one point you can actually choose to NOT take the lost fragment of your soul back.
So the two games are actually immensely different.