GW2's entire shtick is the open world. The vast majority of players spend most of their time in the open world, and the game is designed to facilitate that. Have you ever seen the dungeons GW2 has? They're dead. Like, completely dead. Getting into instanced group content in GW2 is so inconvenient, you'd almost think they did it on purpose. So people spend their time in the OW, and the game rewards them for that. And by reward, I mean it gives them a bunch of trash that people sell to make gold, to do what they actually want to do.

So you have an open world that is always populated, but let's not pretend it doesn't come at the cost of other things.