Earlier quoted context omitted.
You are literally required to get better fill prices than the market with PFOF. You aren't being played any more than if you just send a normal limit order to the market
Why—exactly—do you reason that someone is willing to pay $109 per user per year for their order flow? Put another way, Robinhood’s actual customers are confident that they are able to extract in excess of $109 in value each year they purchase the flow of orders from a given Robinhood user. From where and/or from whom do you suppose this money is being extracted?
My guess is from other funds that aren't privy to what horse the lemmings are betting on today and riding that wave.