America loves it's shooters. COD is literally the entire list on top of Battlefield, Destiny and RDR
Also this is for US not worldwide. I'm sure worldwide other games would crack this list.
For example PUBG sold over 50 million copies
worldwide, far more than any COD(highest sold COD is Black Ops 2010 which sold 30+million yet isn't on this list because this list is just the US.