I don’t think it’s quite that simple. Several major studios have attempted to follow the looter shooter train only to be met with disdain from players for making inferior copies of better games. I think it takes a lot of experience in order to make a game like BG3. Larian have worked their way up to this point learning lots of lessons on the way, and there is a lot going on behind the scenes we aren’t privy to. If EA or Activision or whomever went to one of their studios and said “copy BG3” there is a good chance we will end up with more Anthem, Suicide Squad, Avengers, Godfall situations.
Larian has kind of a perfect storm of factors going into this.
1) They have a couple of large-scale RPG games prior to this, giving them experience.
2) They have a bespoke game engine specifically designed for this kind of game.
3a) They have a small studio structure, which (for better or worse) means that there is a unified vision of what the game should feel like and be, decided by passionate people.
3b) Despite this structure, they have 400 employees all working on the same game.
3c) There is no corporate overseer. There is no outside publisher. No one is calling the shots or trying to manipulate them into utilizing trendy features or chasing some white whale player demographic.
4) They've employed what amounts to an open beta that lasted for years, giving them a huge amount of data on player behaviors that they can use to fine-tune the game.
No EA or Activision or Take Two will be able to do a game like this, because they lack these fundamental elements. Not only can they not do a RPG like this, they can't pull off a game of this size and complexity of any genre!
5) To top it all off, this RPG happens to be an IP that is experiencing a surge in popularity and pop culture recognition
I'm not saying that BG3 can't fail, but literally no mega-corporation could make BG3 better.