Ehhh, if the space was small and had things in it, maybe. But when you wander around the overworld in most FF games, there is trout all else going on. You are it. I could walk around the inside of my bathroom, but that doesn't mean there's things going on.

We'll look at the inside of FF games, for example. There are often NPCs on predetermined paths walking around. That is infinitely better than having a bunch of people just standing around. The next step up from that is something like Oblivion where the characters go other places too! It makes everything come alive, rather than just being a canvas for you to paint all over with your actions.

I kind of digressed there but my point is that even a couple of airships in the sky, a huge sky, makes things feel more populated and alive than smaller spaces and a lack of "stuff" would.