>>52564578Like Hoenn, it's squarely focused on bringing to life a specific regional identity. Unlike Hoenn, which is unfortunately dragged down by its identity involving a lot of water, Sinnoh's mountainous focus doesn't negatively impact the adventure for most people. Mt. Coronet being this centerpiece that opens up more as you go makes the region feel more cohesive and alive rather than just a linear video game.
There's also a ton of things in Sinnoh that exist purely for atmosphere. They were really building up Pokemon as larger than life at this point. There's a church in there, for god's sake. The Japan-based regions also feel a lot less like travel logs thanks to being something familiar to the developers, so Sinnoh is obviously going to be the most refined example of balancing a tourist and native perspective.