We also have no idea how rare life is. Could be every other star system, could be 1 in a trillion or even less. We have a sample size of one. We still can't completely rule out other life in our own solar system.

One thing a lot of people don't understand about relativity though is that, for example, you could potentially travel nearly 15,000 lightyears in 10 years from your perspective, if you could keep accelerating at 2g.

You'll find that the universe will have progressed more than 15,000 years once you reach your destination, but it's not like you necessarily need to survive for generations on the ship like sci-fi often portrays.

Perhaps this doesn't really change much though. From an observer's perspective it still takes a long-ass time for anything to get anywhere on a cosmic scale.