The idea is not to avoid black swan events entirely, it is to have pockets that are missed by a given event. Earth goes cold? Well, good thing the moon base can preserve technology and knowledge for a hundred years. Solar flare? Good thing we have the under-ice base on Europa. Europa explodes? Good thing that we are still on Earth. Now if they all happen at the same time, like the sun dying, then that is why you want to get a star base even further away.