Adam Smith was well aware that the rich man spent a smaller percent of his income on his mansion than the poor man did in his shack. The rich person also has, statistically speaking, a year’s income in liquid cash, a few mil in stocks and bonds, some expensive cars, maybe a boat, some expensive sports hobbies, a travel budget, good food at all times, and a will to divvy up all the wealth among their children.
You will die, some religions will let you take it with you, but none that are popular today. So you may as well spend whatever you earn on things that you think will make you happy.