Besides, installed base doesn't actually matter as much as people think. Most games early into a console lifecycle will have significantly higher attach rates than later releases.
It's so nice to see this typed out.
Install base matters significantly more when it comes to evergreen games that never leave charts and have loooong legs, because those are games that are in the GTAV category of "what most gamers buy when they buy a console."
But core games that sell a vast majority of its sales in the first 2-3 months? The ability for the game to sell and move units for that particular audience is the driver. And it's been demonstrated many times this gen, when games like Titanfall sell ridiculously well despite its low install base, Gravity Rush 2 performs terribly in spite of its install base, among other things.