Fermi, along with the others sitting around eating lunch that day, came up with the great filter idea. The theory being that any intelligent life would discovery weapons with which they could destroy themselves long before they came up with a way to travel the massive cosmos.
The question then became can anyone keep from killing themselves off long enough to get to the technolocical phase needed to colonize the cosmos.
Silly conclusion.
Considering how many stars there are and that most of them have planet systems, many with earth type planets it would be logical that there is life in the galaxy.
However, the above being said consider that the galaxy is some 10 or so billion years old. Consider that we search for life, intelligent life by searching for electromagnetic radiation. Humans have only been on earth which is just over 4 billion years old, for about 10000 years in which they have made records. Of that 10,000 years or so it has only been in the last 100 years that we have used electromagnetic radiation. In another 100 years we may have abandoned that type of radiation for communications as being too slow.
We do not have the capacity to understand life beyond our own yet. If there were a planet only 1 million years older than ours that would mean the people are a million years ahead of us. If they don’t want us to see them we won’t.