Such leisurely 100,000 light year trips aren’t going to appeal to biological passengers who will die long before their destination is reached. Machines, on the other hand, won’t complain if they’re cooped up in a spaceship for tens of thousands of years. They don’t require food, oxygen, sanitation or entertainment. And they don’t insist on a round-trip ticket. Face it we make stinky toxins the rest of the universe might hate.