During each generation of rich people about 20% go bankrupt. Maybe they are alcoholics or they are fools who fall for scams. Your example would come close — a person who is not especially wealthy and who doesn’t work and who consumes 100% of their income. That would put them at a heightened risk of dropping out of the category of the wealthy.

A better example would be 2 people who work and who both make $100,000 and who consume 100% of their labor income. But one of these individuals has a $1 million endowment and reinvests every penny earned from interest. You can see how that would accelerate the concentration of wealth.