I would be very interested in hearing what benefit studio like Larian has in building their own engine, over using a another one.
Mostly being able to reuse code and APIs specific to the turn based CRPG genre instead of having to create those from scratch on a generic engine. The "best" engine for a company will always be the one which will be the most profitable in the long term. That is why Bethesda keep reusing Gamebryo even for future release like Starfield, if it ain't broke, don't fix it.
