I hadn’t even thought about preferences for photorealism being a streamlining thing, but it does fit the idea.

I think it’s also a risk aversion thing as well. Few people will complain about a game looking realistic, so it’s very low risk from the point of view of publishers/investors/marketing. Most people will prefer a unique and stylized look that meshes with the game, but investors and marketing teams can’t be sure in any given case, so it’s written off as a risk.