Because the three of them are all making their store business decisions outside of CA such that it's far harder to have California law applied to them?

Epic also sued both Google and Apple in Australia, which is notably outside of CA.

https://www.reuters.com/legal/litigation/australia-court-rul...

I think the simpler answer is that Epic isn’t upset with the arrangement they have with Microsoft/Nintendo/Sony. They’ve done a better job cultivating a relationship with Epic than Apple has who seems to have only contempt for every other developer.

https://direct.playstation.com/en-gb/buy-consoles/playstatio...

https://www.amazon.co.uk/Ubcwin-Switch-Fortnite-Wildcat-Bund...