Happy birthday. And I wonder if the dynamic that is present when we are young carries over when we are adults. If your brother was the first born, there were many milestones of his for your parents. His first word, first time he walked, even the first time he used the toilet were possibly notable milestones for your parents also, helping to prove their parenting skills. By the time the second and subsequent children accomplish these things the novelty may have worn off. I wonder if that carries over to birthdays that are milestones.
Or perhaps because your brother disposed of the Gold Cup they just said forget shopping, give them some cash.
I never talked to anyone who had to fire their gun who said "I wished I had the smaller gun and fewer rounds with me" Just because you find a hundred people who agree with you on the internet does not mean you're right.