i remember reading that buddha is depicted as fat to show abundance

here's a direct quote off google search on why is buddha shown as fat? ""he is included among the Seven Lucky Gods of Japan as a harbinger of abundance"

so the idea there is nothing is missing or lacking including all the food one wants, so a big bag of gold or coins makes sense as it goes along with that idea of abundance.

it's like how in india, the rich wear white as it shows they don't have to do any kind of work where they may get dirty, the fat buddha shows he has all the food he wants, to be fat in some poor countries shows wealth as you have an abundance of food where many don't get enough food to eat.