Because all my statements about split screen are actually just coming from general knowledge about game development and working on a network multiplayer game and assuming what would not be needed in local co-op I actually did some research about this topic now to make sure I didn't had false assumptions here.

This video here shows one Implementation of split screen https://youtu.be/tkBgYD0R8R4 of course this could be implemented differently by larian studios but I'm pretty sure the basic principle stays the same.

And the basic principle is not running the game two times. It's running two Views at the same time in the same world. So obviously there is no need to have everything twice in memory. So right now I don't see anything about what I said about split screen being proven wrong.

Of course there will be more load on the hardware for two players split screen but it's not the game running two times.

No questions that the a slower RAM compared to X or PS5 is causing bottleneck on the series S, never denied this, but this bottlenecks will go down in FPS performance and all of this can be worked around by developers by "optimising" the game. At which point this optimisation is seen as reduction in quality is up to debate. That's what I want to say.