The reason EA stopped forcing all their studios to use Frostbite was that it had repeatedly been shown to be WHOLLY inadequate for a bunch of different types of gameplay, with a bunch of studios working on various games having to independently solve the same problems with different bodges, resulting in loads of delays as they needed to rescope projects, scale them back, or if you were the Dragon Age team, spend some time reassigned as a support studio to show folks some of the workarounds for doing basic stuff which you had to MacGyver together when working on Inquisition.
