I'm not sure I want to get into this game since we're digressing, but if you are talking about reactivity, I think even though it's 20 years old, bg2 is still better. It is more limited, but the story is more cohesive for it.
Well, the examples I have provided are from my playthroughs. In both BG1 and 2 one of my characters was tempted by their divine blood in the dreams. Yet because the developers decided to not implement mechanic where your deeds impact alignment, giving into those dreams meant nothing because only rangers and paladins can fall. And I wasn't playing either. Instead the devs chose to implement a "reputation" system, which could be gamed worse than BG3 barrels (and I suspect this was the purpose of it). I didn't do that and so my murderous character was hunted for being a criminal, yet this also had no impact on the main story. (What is ironic is that my good character in BG2 was killed for playing good, simply because in that particular quest the writers decided thid is not allowed since it would limit the thieves vs. vamps choice to only vamps.)
In BG1 and 2 either your character fits into how the writers decided charname would act, or they don't. In which case the story feels too disconnected from the main character to call it cohesive.
And I disagree this is worse in BG3; I think it is too early to tell, because for now we don't know if giving into the tadpole or abstaining will shape the main plot.
Let's say Larian fails to implement any consequences to the tadpole usage except for what is already there: the dreams. Larian could remove the origin characters being origins. This would still not make the story focus on the protagonist more, in the absence of reactivity towards that protagonist. Because whether you used the tadpole or not would ultimately not matter for the story. Just like it didn't matter with the Bhaalspawn powers, including the slayer. Whereas for example custom backgrounds or other tags, which would be inaccessible to origin characters, could make the story more character-driven.