You can choose to play an origin character, which by default, will have hard coded lore assigned to them. This changes interactions.
Depending on the characters you drag around in your party your interactions and situations change.
The issues with the "Origin system" are its implications on the overall production, the way it weights on other features (or the lack of them) and not that people feel forced to make use of it.
The thing is simple: would I prefer a large cast of characters, with a high amount of situational reactivity and interactivity, or would I prefer an incredibly limited selection of potential party members, because having to make each one of them also an "Origin character" makes them exponentially more expensive to create? To each one his own, but I don't feel particularly conflicted in picking the former.
And even putting that aside, even taking the cast entirely out of the equation, I'd prefer to see that SIGNIFICANT extra budget expected to turn any companion into an "Origin story" written from an entire new perspective being spent on several other things, like that proper day/night cycle Larian dismissed from the get go as "not worth the effort". Well, FUCK IT; it was going to be well more worth than "I can replay the whole thing LARPING as one of my former companions in the last playthrough".
Why? Because I'm perfectly fine experiencing the narrative of each companion just as... you know, a companions. Not just because "I want myself to be a blank slate" (not really something I feel particularly strongly about), but more than anything because it's also the version of the narrative where they actually shine and show hints of having a proper personality, because when you play as them, A) you skip their voice acting B) you take decisions in their places C) you react to events as you would and not a they would according to their writing, etc.
As I said months ago in one of the first replies in this thread, never once playing any of my favorite CRPGs of the past I've ever found myself thinking "Oh sure, the companions in Baldur's gate 2/Kingmaker,/Dragon Age/Mask of the Betrayer/whatever were great, but I mourn the lack of options to replay the entire game as one of them". I stand by that claim: it never happened, and I'm fairly confident it won't happen in the future, either. More than relying on feelings: I put it to test with DOS 2 and guess what? It did absolutely nothing for me there, either.