The next fight is going to be around the multiplayer subscription services I believe. XBL vs PSN vs Switch Online. The value proposition just isn't there anymore:
- PSN free monthly games from 4 to 2
- XBL putting FTP games behind subscription pay wall
- XBL not required (yet) on PC even though cross play games now exist across Xbox and PC
- Switch Online is the only service to offer real value, with the continued expanding selection of NES games
I would not put it past MS to make XBL required for xCloud streaming, meaning that's two mandatory subs for one service, since you'll need multiplayer access for a big chunk of streaming games (I doubt they would segment games between single and multiplayer, and folks getting half of a game will surely balk at the idea).
And MS is starting to get a bit like Netflix in that, it all comes down to their first party content. Once these third parties pull back games into their own streaming services, the game selection will boil down to the MGS output, which is still a wild card. And if those studios are making considerations in their game designs specifically for GP, will the games they offer have enough interest by mainstream consumers? Or would MS be happy to have a niche market?
Not all third party pubs will have their own subscription services, but like Disney+, Time Warner, and eventually Comcast, it's trending in that direction (look at Uplay+, EA Access, etc.).
It still boils down to the quality and appeal of the games. Games sold hardware, they'll also sell xCloud, PSNow, XBL and PSN.