My theory is that we just didn’t look long enough. It took earth 2-3 billion years to evolve from nothing to humans to this stage. So we essentially just start

My theory is that we just didn’t look long enough. It took earth 2-3 billion years to evolve from nothing to humans to this stage. So we essentially just started to see for the first time and we see nothing. A blink of an eye in the time frame of the universe. The distance also plays into the time frame because a civilization may only broadcast for 2-3000 years before new tech is used and that is easy to not be in the right place at the right time.