But: nihilism is also a myth. Some things DO matter. You just have to figure out what matters to you…. even if it’s nihilism.
So is belief in the other stuff. Ultimately, it’s belief in systems. Even nihilism is belief in a system-which-lacks-purpose-and-meaning. But it’s still belief in a system.
Putting my own beliefs to the fire, I believe most things can be thought of as systems. It’s a mythology I hold to as-if fact.