He gets to live comfortably without needing to do that many household chores himself. He also gets help with studies if necessary. No need to mention about suffering from loneliness, though he may need to deal with being subjected to teasing. It's indeed a pretty good deal for him to live there.
Is it just me, or does it sometimes seem like this series gives Minori "main wife" status? I guess she's closest to him in age, but...isn't she also the worst of the 3? Still good, but, the other two are better.