If you cannot see the similarities between the two stories then I think you are purposefully being a bit obtuse.
Does that mean they will continue on being very similar? No.
Is that necessarily a bad thing? No.
But there are fundamental similarities that exist between the two games. I honestly think a lot of it is brought on by making companions also be able to be 'origin characters'. This is a concept that I like, but I never quite understand why Larian has to make every origin character sort of have the same plight... or at least it is something they seem to struggle with in their last two games. Everyone needs to escape the ship, get the collar off/parasite out and deal with a very similar big bad. Then after a while their paths diverge, even though the same major overarching plot applies to them. But it seems like they could just be very different from the beginning. Like I see no reason why they have to share the burden of the collar or parasite - this mechanism is not necessary for having a similar goal toward the end of the game.
But eh - it is what it is. I loved D:OS2, one of my top 2 favorite games of all-time with The Witcher 3. I really like Baldur's Gate 3 so far. You can offer criticism without hating something.
