Our universe is a very large place and may very well be crawling with life. Our universe is about 15 billion years old, and nearly 12 billion of those years passed before life sprang up on Earth. Another 3.8 billion years passed before the first sentient being arrived. If we are destroyed by one of the aforementioned catastrophes, the universe may have to wait another 15 billion years or longer for sentient beings to return. Or life may never return to the universe.
Life is precious.
We must take measures to protect this precious commodity. People often wonder why we exist. The answer is simple. Mother Nature waited patiently 15 billion years for a species to arise capable of bringing life to the rest of the universe. No other species that we know of can accomplish this monumental and noble task.