Modern gaming seems to be centred around size, play-time, graphics and worth. All this encompasses world size, for RPG’s like Skyrim, sandboxes like GTA, Assassins Creed and Far Cry and many many more. Now to me the size of a game doesn’t matter, people that throw around the “this games map is 1.5x bigger” or “yeah well GTA V can fit like 3 Red Dead’s” seem to miss the point. An open world doesn’t need to be big.
Open world games allow for freedom, it’s in the name. The player can make their own choices, go in any direction they want and ignore what they please. So if it takes 20 minutes to get from one side to another or an hour it doesn’t matter, it’s about what happens on such a journey.
For example Breath of the Wild has a lot of verticality, so does the assassins creed series, this allows for interesting gameplay in climbing mountains, buildings and more across their open worlds. Meaning that the actual size has no bearing on the experience of exploring the world. That’s one of the keys, the way you explore the world is what makes the open world interesting, not its size. Also for example Crackdown uses its sandbox very well, as exploration of their cities is tied to in game progress (similarly to BotW’s stamina) in the orbs, the more green orbs you have, the more places you can go and thus you return to those places, meaning the size isn’t key to enjoyment.
Another key to open world is the content. There is no point in having a massive map if there is nothing to do, or it’s manotonous tasks (looking at the AC series here) that are boring. You need to have a variety of interesting environments and activities to do, for example GTA V gives you the ability to do literally anything, explore, play missions, shop, use cheats, go on a rampage, or even make your own mini games for fun. Skyrim fills its word to the brim with thousands of avenues of character progress and exploration, with way too many to list. So games don’t need a large map, just interesting things to do.
In the end it isn’t about have a huge map, it’s how it’s used, the content in it, it’s design as a reflection of gameplay or just if it looks beautiful. When a player is travelling across the map, the bigger it is and the less interesting it is means the player won’t enjoy themselves. So smaller maps with intrigue are the way to go.