A AAA game will have these kinds of details today, because it's expected by customers. AAA(A) games that don't (looking at you, Ubisoft, with your shoddy animations) get relentlessly mocked unless they excel in every other area. First party Sony titles in particular are expected to push technical boundaries (at least of their hardware) in some way or another. That's part of the reason why people are buying these games and the systems they are running on. This isn't an optional thing, it's not a choice, it's the baseline.

You also have to consider that even if this wasn't the case, you can't just radically change the way studios are being organized. Large studios are art-heavy in terms of their manpower, in large part because it's very easy to produce tons of game assets in parallel. It's not easy to hire or retrain people after a switch in priorities and it's much more difficult to apply the same kind of manpower to game design tasks. The old saying that nine women can't birth a baby in one month applies here as well.

Taking a rough look at the credits, Horizon Zero Dawn had 30 designers working on it (world, quest, writing, etc.). Compare this to 57 coders coding things and 148 artists creating audio and visual assets. There are other departments like production, marketing, HR, etc. that I'm not counting, but I think you get the picture.