Sure, it is arbitrary to care about what actually exists and what will actually happen, as opposed to (for example) running your life around trying to optimize the state of Tolkein’s Middle Earth.
But you do care about optimizing Middle Earth (let it be Middle Earth with Halting Oracles to be sure), to some tiny extent, even though it doesn’t exist at all.
But you do care about optimizing Middle Earth (let it be Middle Earth with Halting Oracles to be sure), to some tiny extent, even though it doesn’t exist at all.