You are assuming that we are not taking steps to reach them. Getting there would be time and energy consuming in today’s terms, but while some scientists are looking through the telescope and discovering these planets, other scientists and engineers, who may not be directly linked to cosmology, are developing new technology every day and somewhere someone will make a technological discovery that could make space travel more feasible.

It may not be obvious at first but we have been taking steps. The first half of the 20th century lead to the development of liquid propellant rockets that were later used in WW II. This, then, became the technology that sent humans to space and put humans on the moon and the first space station, the Soviet Salyut 1, in orbit in 1971. The Mars Pathfinder mission landed a rover on Mars in 1997 and more have landed since.

Also, looking outside of our own planet gives us a better understanding of the universe, and of our own planet and resources. Looking at the stars, particularly our sun, was an important step to understanding atomic fusion and the energy derived from it.

Life as we know it is carbon-based. and water-dependent. Hypothetical forms of life have been proposed, using silicon and some metal compounds instead of carbon. We haven’t found them on Earth, but what if we find them somewhere else? What would that mean for our understanding of medicine and the future of life?

You can’t be certain of what new discoveries await. You can be certain that if you don’t look, you won’t find.