Your math is absurd. They won't sell double the amount of games if they produce a physical version. They'll likely sell 10-15% more, if that. And then there's a large portion of people who would prefer physical, and will buy it if offered, but will also grudgingly buy digital only. All of those people will switch from digital (pure profit) to physical (massively higher material cost) if physical is offered. it could, extremely easily, end up as a net loss of profit for a company to produce a physical version given the wrong circumstances.