Hard to believe that, in this day and age, folks still believe in the zero-sum fallacy.
Not a fallacy, in this instance.
Let us assume Walmart sales average $100M per store in a year.
Three stores open in DC, with total annual sales of $300M.
Do you seriously contend that the city’s population suddenly spends $300M more than the previous year for toothpaste and T-shirts? Most, effectively all, of that $300M will come from other stores’ lost business.
You have just expressed a zero-sum fallacy fallacy.
The true zero-sum fallacy is that any one person or organization in the economy gaining business must result in a loss for someone else, that there is only so much wealth to go around.
What I am pointing out is that in any given market, while a zero-sum is not applicable, the total sales are quite inelastic. If McDonalds increases its sales by $10B, it generally means most of that is from reduced sales to other fast food outlets, not that the world suddenly decided to spend $10B on lousy hamburgers.