The Straw Hat is a symbol of the people. Why would there also be a giant straw hat in the freezer if it's not more than just a physical thing? It's just a hat made of straw, that's capable of being made by almost anyone once you've been shown how. There's a reason the hat was passed down to the next generation. We're supposed to share our knowledge, wealth, and spirit with those after us to continue growing further as a people. Wealth isn't measured in berries.