Interstellar travel has been feasible since the first rocket was lit by the Chinese. You must be mistaking interstellar travel with faster than light travel. There is no need to travel faster than light to get to another star or colonize the galaxy. There are at least 2 ways to get to another star, you can send people or something that will become people. The first is tough, the second should be fairly simple and neither requires travelling faster than light (although in the first the original crew will not be the ones that reach their destination). In fact if there is any terrestrial life attached to the Voyagers we may have already done the second.The Fermi paradox argument makes way too many assumptions. Besides the ones others have mentioned, there's the assumption that interstellar travel is feasible, which we don't know for sure.... .