Previous BG games had settings for companion AI behaviour (even if it was purely combat focused).
It was a necessary evil.
Controlling every single combat action for every single party member could get tedious.
Bioware struggled with translating D&D mechanics (where each character is controlled by one player) to a single player but party-based video game without it getting tedious, so they arranged it so that you could automate parts of the combat.
Later Bioware games evolved this further. For example, in Mass Effect, your companions will perform standard combat actions on their own, but you could issue commands and you were responsible for telling them when to use their most powerful abilities. Additionally, when it came to loot, you would automatically pick up loot as soon as enemies are defeated. They realised some parts of the game are boring, and tried to address that with automation.
So "automating" stuff is one way to solve the problem, but it is a waste of development resources to design parts of the game (eg meticulously placing environment loot) that will not be manually interacted with. Automation is also inferior to just
fixing the game element, ie making it fun.
I do agree it might be nice for there to be a "feeling" of characters having personality during exploration. However, I think there might be a bit too much that can go wrong in terms of companions triggering traps, etc, for this to be implemented in a manner you'd be satisfied with.
I'd be satisfied with having better control over party formation while also having a bit of
party banter.
