Not necessarily. I was never the type to trade in physical games, but recently for Forza 6 I could either pay $99AUD to "own" the game, or buy one month of the PC game pass for $15AUD. An obvious choice.
The friend I played the game with did the same. Honestly, if they didn't include Forza 6 in Game Pass we both would've purchased it full price.
I see what you mean, but I think gamers on a budget will cancel. Other gamers would've paid full price for 12 games and instead paid $15 each for 12 games.