It is possible that game streaming services like Google Stadia and Playstation Now may someday offer different game category packages for gamers who want to save money by just paying money to subscribe to a few game category like first person shooters and RPG, and not needing to pay to subscribe to games with categories like puzzle and casual games which they are unlikely to play.
Only paying for a few category packages are popular with Cable TV subscribers who just want to subscribe to sports and movie channels, and local TV channels which they are required to subscribe to.
Letting subscribers only pick certain game categories like shooting games can also cause more people to subscribe because some subscribers may only want to pay for shooting games, but they don't want any of their money going to categories of games like casual games which they don't like.
It may also get competitive where subscribers of shooter games try to convince more people to subscribe to shooter games, and subscribers of action games convince more people to subscribe to action game categories, so there is enough money, and players to make new games for a certain category.
Obviously none of us know what Stadia is planning at present but that could be a good idea as an option. However if Stadia is only $20 per month or so as seems to be the case then will a small discount be worth it? For immensely popular games like shooters they would ask more, because you obviously can’t offer a shooter at the same rate as a 2D Puzzle. At which point you’re probably looking at $10 to $15 per months, not exactly critical.
I think some gamers would prefer to pay less to subscribe to one category, and a few other game categories I am interested in. After a year, users who subscribe to only one or a few game category can end up saving $50 or more money after a year of subscribing to game streaming services like Google Stadia. $50 is sometimes a lot of money if a user live in a poorer country, or the user is poor.
Some streaming games may have DLC and in-game purchases like in-game money, so the money savings from subscribing to only one category can be used to buy DLC, and in-game money for the games they actively pay.
