Comparing to the price of console games plus price of console it's free.
I don't know how much longer the game industry can expect its target audience to spend $60 each on piles of games. Things have been trending towards freemium for long enough that it almost seems weird when the game that everyone's playing is not free(ish).
My point being, if enough people aren't buying console+game anymore, would the opportunity cost of doing it on mobile instead be that bad?