To scale up the principle a little... Uber acts like a real estate agent, they charge the seller a percentage of the total for the service of connecting a buyer and a seller.
Imagine you were selling a house, and your agent came to you with an offer of $1M, of which they would take a 10% commission. You agree to this, but find out later that the buyer actually offered $1.1M. The fact that each party agreed to the transaction with the real estate agent isn't relevant here. What is relevant is that if you charge for services based on a percentage of the price, you can't then set different prices at both ends, this strongly violates the expectations of the contract.
Looking at https://www.uber.com/info/how-much-do-drivers-with-uber-make..., it says "Drivers using the partner app are charged an Uber Fee as a percentage of each trip fare." This is analogous to the real estate agent example, and this is why this is fraud on Uber's behalf. If they told drivers that they were simply buying their services for an arbitrary price, then it would be fine, but they don't say that.
Imagine you were selling a house, and your agent came to you with an offer of $1M, of which they would take a 10% commission. You agree to this, but find out later that the buyer actually offered $1.1M. The fact that each party agreed to the transaction with the real estate agent isn't relevant here. What is relevant is that if you charge for services based on a percentage of the price, you can't then set different prices at both ends, this strongly violates the expectations of the contract.
Looking at https://www.uber.com/info/how-much-do-drivers-with-uber-make..., it says "Drivers using the partner app are charged an Uber Fee as a percentage of each trip fare." This is analogous to the real estate agent example, and this is why this is fraud on Uber's behalf. If they told drivers that they were simply buying their services for an arbitrary price, then it would be fine, but they don't say that.