I can provide you with information based on current scientific understanding.
The vastness of the universe and the challenges associated with interstellar travel are indeed factors that could contribute to the absence of direct contact with extraterrestrial civilizations. The universe is incredibly vast, with billions of galaxies, each containing billions of stars. The distances between these celestial objects are enormous.
Given our current understanding of physics, the speed of light is considered an ultimate speed limit. As I mentioned earlier, according to Einstein's theory of relativity, objects with mass cannot accelerate to or exceed the speed of light. This limitation makes interstellar travel a significant challenge, as it would require vast amounts of energy and time.
The distances between star systems are so immense that even traveling at a significant fraction of the speed of light would take a substantial amount of time to reach other star systems. Additionally, there are numerous other technical challenges to consider, such as energy requirements, the effects of acceleration on occupants, and potential hazards encountered during space travel.
Considering these factors, it is possible that the vastness of the universe and the limitations imposed by the speed of light are reasons why we haven't had direct contact with extraterrestrial civilizations, if they exist. It's important to remember that our understanding of the universe is still evolving, and there is much we have yet to discover.