Baby sleeping in your room

I’m just curious some reasons why some decide to keep their babies in their rooms at night until they’re several months old or even a year or more. I guess I just don’t understand why. My baby went into his own room and crib with a monitor and Owlet at six weeks. Someone mind sharing? I guess I just kind of feel like it would be so much harder trying to stay quiet, keep the lights off, etc... What’s the point?