Do you mean something like this?
Which is currently science fiction, as opposed to scientific reality like this:
The answer to that is not until we start doing stuff like this to provide the raw materials needed for such ambitious projects.
Which can only happen when we have a launch system that lowers the cost of getting into space to the point where it becomes trivial, rather than the huge hurdle it currently is.
That’s why we need things like this to enable the process.
If you want to know why so many people are watching SpaceX so closely, it’s because what they’re doing is developing the system that will allow our sci-fi dreams to come true.