Having companions interact with each other and the world beyond their personal quest(s) is one of the easiest way to make them feel alive and as actual characters in the world. I was surprised to see how little interaction there's between the characters in Larian's most recent game, especially since it's actually a step down from the first Original Sin game which already had very sparse amounts of interactions between the companions. I'm guessing this is a by-product of Larian developing the different stories and characters with co-op gameplay in mind which is why whenever the party gets together to discuss a topic (most often related to the main story) each character just chimes in with one line and goes back to being a puppet. Furthermore, by letting people play
as one of the important characters a lot of their personality, back story, thoughts etc. are left to the player rather than the game's canon.
At PAX East Swen admitted that the relationships between the characters [in Original Sin 2] weren't as evolved as they had wanted and that they would focus very heavily on that in the next game they were making.
[LINK]This was a couple of months before BG3's official announcement, so we can assume he was talking about that game. It sounds like one of the other attendees misinterprets Swen's statement as him referring to the romance aspect of relationships which results in the already short conversation steering away from the initial topic.
Either way it appears that Swen/Larian were aware of the importance of character relationships in their upcoming title (which we now know to be BG3) and has been working on improving them.
On a different note, something else I like about the BG series' companion quests are that many of them can be resolved early on instead of all the companion quests leading to the same final area of the game where everything related to their personal quest 'coincidentally' is located. I feel this also helps set the scale of the world and adds an element of realism to the companions' respective stories.
