Is the pattern a quality library of different genres? What do I win for getting it right?
Wow, lots of great games with loads of replay value across different genres, and these aren't even their big titles. Sounds terrible.
Look, we all have different tastes in games. Personally I love stuff like Wasteland 3, battletoads, Grounded as well a AAA game like TLOU2. Only thing I'm saying is that Sony and MS are going with completely different strategies and it will show in the types of games they'll be focusing on.
Sony is all about story telling and single player blockbusters. If you don't like those sort of games, you're in luck because they wouldn't work with the GP model. MS will be about quantity, smaller scale games and experiences that keep people engaged with GP over a long period of time. Elder Scrolls Online, Tell me Why... perfect games for GP. Doom Eternal, Gear 5.. not so much.
The thing you don't seem (or don't want) to understand is that for ANY subscription-based model to be able to keep people subscribed you need to offer two things: Quality and variety.
Variety: If they only offer GAAS as you say, people who don't like that will just go away.
Quality: If people don't like what they offer, they will just go somewhere else to find it. And no, people will not keep paying "just because is cheap." You yourself have said MULTIPLE times that you just subscribe whenever a game that interests you comes in and then unsubscribe again.
Oh, and Halo is not simply going GAAS. They have said multiple times that the single-player campaign will be "the longest yet." So I ask you, if Sony provides you a satisfying single-player campaign on the next Spiderman, but then they keep adding stuff over the years on top of it, will you see that as a bad thing?