As much as I like Re:Zero, I just don't understand why it is hyped up as much as it is (its like a 7.5/10 for me). Subaru really isn't "realistic" at all. And honestly when it comes world building, I'd argue there has been very little. To me it just seems like a generic fantasy world. We really don't know much about the land and the only world building that has been done is really just plot exposition or just there to foreshadow, but rarely truly adds to the world. Compare it to Ascendence of a Bookworm, Log Horizon, Legend of Galactic Heroes, Magi, and so many more anime. They all did a much better job at world building. Not were able to establish a so many things about the world much sooner to make it seem unique and alive in a much quicker/sooner time.