Even if the companies never expand and the stocks are priced perfectly the market is not zero-sum. It's still an asset that produces value and pays back every y

Even if the companies never expand and the stocks are priced perfectly the market is not zero-sum. It's still an asset that produces value and pays back every year. There are people for whom it makes sense to own something that gives steady returns and there are people who for whom it makes sense to have cash on hand. Trading might be zero-sum which is great for everyone but owning stocks isn't.