How different are "all across the world" and "all of the world"?
"All across the world" means that something originates from a large diversity of places around the world. This implies that something comes from multiple places in the world and not just one or a few. You can replace this expression with "all over the world" or "all around the world" to have the same meaning. Ex: The zoo has animals from all across the world. "All of the world", on the other hand, includes everyone in the world. If you were to say, "guests from all of the world", this would imply that the guests come from every part of the world and no part is left out. Ex: All of the world has been affected by the pandemic.