Just my subjective opinion to add, but I think they also succeeded at making the open world itself feel more puzzle-like, as opposed to the general set dressing it provides in a lot of RPGs. Being in a cold/hot/mountainous/wet/etc area is meaningful for the impact it has on your ability to explore.

I feel like it just gives a better sense of engaging with the environment, as opposed to engaging in the environment, if that makes sense.