It was well publicized that there were different ways to get the new iPhone X on November 3.
One of them was to take your chance with a preorder...that you would get one before they sold out online. You took this chance and missed out on November 3rd delivery, others didn't miss out.
Another was to take your chance and walk in to an Apple store or cellular company on November 3rd. Your brother took this chance and got one, while others that took this chance did not get one.
Pretty simple.