Why do people do. Nurseries for newborns?!

I'm not judging anyone at all firstly, but I genuinely don't understand why people do a separate room or nursery for their newborn babies. Are there really people who put their new baby to sleep in a different room? That seems so weird and terrifying to me. I mean once the baby is like a year or so sure but I don't understand why everyone posts nursery pics while pregnant.. What is the point of doing a room that won't be used? I can't imagine how I'd ever relax with my baby in another room it just seems crazy.

I'm not necessarily criticising anyone I just don't get it 🤷🏼‍♀️