If memory serves correctly, the growth period of the Bizarre seems to be just about this lengthy. In other words, while the Bizarre hasn't yet achieved faster-than-light flight, it already possesses the capability to traverse star domains.
Perhaps in a few decades, or maybe in a century, it will eventually grow to the point of eroding this star system. By then, humanity's only option will be to flee from the Bizarre. Fortunately, under the constraints of universal laws, the speed of light is unbreakable, meaning that no matter how advanced the Bizarre grows, it will be hard-pressed to catch up with humanity's escape velocity.
Through microscopic projection technology, we can observe that there's still ample time. However, as of today, Blade Warrior continues to be deeply troubled by this matter. She has no idea what stage the Bizarre has currently reached—could it have grown so terrifying that it's now capable of instantly eliminating Sky Shadow or even Roland?