The universe is more vast than you could imagine. The chances for a more advanced life form than us humans are near 100% too.
I like Neil DeGrasse Tyson's reasoning on this.
We don't live in a Star Wars or Star Trek universe where traveling across a galaxy is a trivial task.
The Star Trek universe is a type 2 civilisation. "Traveling across a galaxy is not a trivial task" -> to us it isn't. Would anyone from the 16th have thought that traveling the world in matters of hours would be possible? Not really. What lies ahead we don't know. We do know that technology advances exponentially. By that logic, at some point, a civilisation should reach the means of intergalactic spacetravel.
And might I add any scientific theory or proven fact starts with assumptions.
And your conception of space travel might be completely erroneous, who knows !? Maybe we don't need to go past light-speed, maybe we'll figure out how to distord matter (in the large sense of the term), or distord space & time, or send physical matter through very long distances, or whatever solution that sounds crazy for us now.
If space truly is limitless