Do you think that it is riskier for Sony to keep pushing single player games that are acclaimed and sell well, while being almost the solo triple A story driven big published/maker out there, which now is Playstation biggest moving force with the hardcore gamers, than Xbox to dabble in an extreme competitive and saturated market that they have little consolidation?
The whole premisse of Sony being left out on the GAAS market is flawed.... Because GAAS are made by third party, and Playstation will get those. Also, GAAS have to be on various platforms, for example: Apex is the biggest one for EA, you can play on everything (Switch is coming), so is Fortnite from Epic, LOL running on potato pc's and coming to mobile and consoles, Free Fire on mobiles running on anything.... GAAS needs to be everywhere to stay relevant these days, they need a shit ton of players playing every day.
Halo Infinite as GAAS has a flaw, that is glaring, Halo Infinite will not be able to compete with Fortnite and Apex, because one of the most important things that all gaas needs is player retention, they need lot's and lot's of people buying skins, characters and playing so the comunity can grow... Halo Infinite is a high end game locked on PC and Xbox, so potato pc players, nintendo and playstation players won't have access... Which means, if some players have to invest on a GAAS, they will rather do on things with more players and probably friends playing it.
Maybe I am wrong, Halo Infinite and others Xbox gaas will be a success, but if they reach Sea of Thieves levels... That would be expected.