That does not follow. Suppose the gig workers are doing food deliveries. Each day, the market places X food orders at a total of $Y including fees and tips. If the market clears (no one who places a food order has it left unfulfilled), a reasonable assumption, then the food delivery gig is a zero-sum game. If all the drivers work more hours that just means they’ll be waiting longer, on average, for orders to come in. No amount of extra hours worked will create additional food orders.