Former Thief designer Randy Smith Evergreen has commented on the graphics "arms race", joking that photorealism could have topped out with 2010's Alan Wake.
But better graphics is something you can just throw money at, while art direction requires skill and letting artists free. From the point of view of investor, putting all in graphics is the les risky choice.
Also it is a lot easier for investors/leadership to see graphics at any point in the process compared to gameplay, which can change all the way up to release and takes time to work. Throwing money at something that can be seen is easy!
But better graphics is something you can just throw money at, while art direction requires skill and letting artists free. From the point of view of investor, putting all in graphics is the les risky choice.
Also it is a lot easier for investors/leadership to see graphics at any point in the process compared to gameplay, which can change all the way up to release and takes time to work. Throwing money at something that can be seen is easy!