Trading is not a zero sum game. It doesn't matter if nothing's being made, that's not the point. It's an important service providing pricing and liquidity which facilitates capital allocation, diversification, and risk management. Trading is an absolutely essential part of the economy.
As a simple example, a farmer hedges his wheat crop selling wheat futures. That allows him to reduce some of his risk, thereby allowing him to plant more (i.e. growing the economy). The market marker who bought the wheat futures may be trading multiple commodities. This trade diversifies his risk, allowing him to trade more of other commodities, allowing other farmers to offset more of their risks (i.e. growing the economy). Investment companies or hedge funds enter the market purchasing futures, to diversify their risks, allowing them to invest more in equity markets, which fund companies (i.e. growing the economy).
If my point isn't already clear, markets and trading facilitate the diversification and allocation of risk capital to market participants thereby growing the economy. It's the conduit for capital which does make something.
As a simple example, a farmer hedges his wheat crop selling wheat futures. That allows him to reduce some of his risk, thereby allowing him to plant more (i.e. growing the economy). The market marker who bought the wheat futures may be trading multiple commodities. This trade diversifies his risk, allowing him to trade more of other commodities, allowing other farmers to offset more of their risks (i.e. growing the economy). Investment companies or hedge funds enter the market purchasing futures, to diversify their risks, allowing them to invest more in equity markets, which fund companies (i.e. growing the economy).
If my point isn't already clear, markets and trading facilitate the diversification and allocation of risk capital to market participants thereby growing the economy. It's the conduit for capital which does make something.