The universe is just far too massive. It’s a statistical improbability that of the hundreds of billions of stars in each of the hundreds of billions of galaxies in our observable universe alone, not a single one harbors intelligent life.

Not only the vastness of space, you also have to consider time.

We not only have to be close enough for space travel, we have to be in the same timeline on a scale of billions of years.

Life is probably abundant in the universe, it’s just too big and too old.