Technically, he didn't refuse to take the real Holy Sword, it's more like he couldn't pull it out. Nevertheless, he decided to go with the replica, consider it the real one and actually defeated the Demon King with it.
With all the plot twists I have read in the previous chapters and other stories, I was expecting that the mother has passed away. This is wholesome though.
Well played author, well played. You had us in the first half, not gonna lie.