Mars is colonized.
We are a tiny dot of life suspended in a nearly infinite universe. Any number of planetary events could happen that would instantly end all life on this planet. It would only take a stray comet or asteroid. And not even a very big one. We are quite vulnerable. We are precariously placed in a galaxy that is indifferent to our survival.
I think the technological leap beyond the next one will take us to the stars. After all, we live in a universe that looks like it has plenty of room into which we can expand. I look for the day when a billion planets are populated with a billion people each.
What will this look like? I think we will learn to conquer distance though a method of which we cannot yet conceive. Then we will launch terraforming nanites into space that land on lifeless rocks and planets and transform them, at the atomic level, to be filled with carbon, hydrogen, oxygen, and everything else we might need. Atmospheres will form, then plants will be seeded, and then the colonists will arrive.
I think we will go forth and fill these billion worlds with generations that in kind will produce their own Dante, Columbus, Copernicus, Da Vinci, Newton, Shakespeare, Bach, Washington, Carver, Curie, Edison, Chaplin, Earhart, Tolkien, and ten thousand more masters in a thousand more arts.
So, far from reaching a point, as some people maintain, where we have exhausted the meager resources of Earth and find ourselves dwindling away, something else entirely different is happening. We are gaining speed, not winding down. We are blooming, not withering. For the greatest natural resource on the planet is the human mind.