The universe is expanding away from the origin of the Big Bang. This has been measured and quantified. Looking through space in the direction of the Big Bang is like looking back in time, in the same way that looking at stars is like looking back in time, since it takes billions of years for that light to get to us. What we see today is not what is currently happening.

Now, it has been theorized that one cannot travel faster than light. The speed of light may be a constant that cannot be broken. If this is true, it would be impossible for other life forms from distant galaxies to be able to reach us, since there is a finite period of time from the Big Bang to now, plus the time it takes for a species to evolve, plus the time it takes to
get to Earth from other galaxies.

None of this precludes the fact there is other life in the universe. Only humans are arrogant enough to believe that

A) all intelligent life wants to travel across space and time;
B) Earth is worth visiting;
C) Intelligent life is interested in seeking out other intelligent life;
D) Humans ought to be considered as an "intelligent species"

For all we know, in the eyes of another species, humans have the collective intelligence of pond scum.