They’ve very likely been traveling this way for billions of years. People simply do no comprehend the vastness of space.
In the old days if you wanted to cross the US you used a covered wagon driven by horses.
(fast forward to some future date)
In the old days if you wanted to cross space you used a spaceship with a rocket engine.
(Clearly you will have to be able to bend space-time to go any distance at all—that technology is not available yet, and may not be for a while—but any advanced alien civilization would have to have it—and that would mean that the vast distances of space would be irrelevant.)