Sort Games By Number of Xbox Live Friends Who Own/Play Each Game in Game Pass
Sort the games in Game Pass by cross referencing it with your Xbox Live Friends list and see how many of them own/play them. In addition, maybe have a referral program with Microsoft Rewards that if you get one of your friends to download a game and they play for a certain amount of time, they each get a reward.
This is something that EA Access has. You open the game's page and it displays friends that have also played the game. This is something that Game Pass needs!
Nicholas Greenwood commented
I had some friends over and we wanted to play some local multiplayer but had no idea what games had local multiplayer without clicking into each game individually and seeing. Adding an option to sort the games by how many players would be really helpful.