Not for a minute, just because there are a billion stars that may have planets don't mean one of them has the exact parameters that's required for life to exist, and thats not news either. In a billion planets that might be around stars maybe only a few hundred have liquid water, and maybe only a few of those have water that is drinkable, and then only a few of those that don't have extreme gravity issues before we even get to the atmosphere issues. There is only one Earth, there might be other planets that are inhabitable but will we ever find the means to get there before natural disasters destroy what life there is here.
The closest star is alpha centauri and its 4.7 light years away, which means if we could travel the speed of light it would take 4.7 years to get there and whats the chance of a planet being there at all yet one we could inhabit.
I think, with all respect, you're underestimating the size of the known universe. It's many, many, times bigger than you think it is; exponentially so. This is true even for astronomers. No matter how big we can apprehend, we just can't apprehend the true size of the known universe. It's a mental limitation we have as humans.
The key is that we know that earth has happened at least once so we can't say it's impossible so much as improbable. Alpha Centauri is actually a triple star system with two of the stars getting as close to each other as Saturn is from the sun. This would make Alpha Centauri unlikely to be able to support an earth-like world as that world would be pretty much cooked by both of its suns. Naturally astronomers are very interested in finding planets in this system, but so far none have been found. Even if we did find one, however, Alpha Centauri is still about 43 trillion miles away despite the fact it's our closest neighbor.
Earth is very lucky. We're in the galactic exurbs. We don't have many neighbors and the ones we do have are quite distant. This is good because it helps protect us from galactic dangers like novas and gamma ray bursts.
The class of star we have in the sun is pretty common. The sun is a very ordinary star going through a very normal life cycle. That's a good thing for us as well because some stars have very violent lives that would make life on any planets difficult. Most stars though, do have one or more companion stars and they orbit each other (like Alpha Centauri A and Alpha Centauri B and their more distant sister, Proxima Centauri). Multiple suns can make life formation very difficult as it would be very easy to have massive temperature changes on any planet revolving around any one of the stars. Not all binary stars have irregular orbits around each other, however. Many have very stable orbits with enough distance between the two to allow a stable Earth-like planet to form.
But that's not always the case. There are likely about 10 billion lone sun-like stars just in this galaxy, just as isolated from the hustle and bustle of the galactic center as we are. And there are likely about
500 billion galaxies in the universe. Now if we simply average that figure of 10 billion times 500 billion, we get 5.0 x10²¹ possible stars that are just like our sun. We also know now that planets aren't all that rare. Current estimates are that out of all stars, 5% have planets but in metal rich stars (like our ordinary, common sun), that figure rises to 20%. That's just an estimate extrapolated from current extrasolar planet findings. As we detect more extrasolar planets, that figure will rise. Finding extra-solar gas giant planets (like Neptune, Saturn or Jupiter) is relatively easy compared to finding comparatively small rocky planets like our own Earth, Mars, or Venus. In any event, finding planets isn't all that easy no matter what kind you're looking for, at least for right now.
Once again, our biggest hurdle is distance; at least in our current ability to detect dimensions. Right now we imagine space travel based upon the four dimensions of time, height, width, and depth. We currently think we have to travel within those dimensions to reach these stars. What's most intriguing is that we may not have to. If the 11 dimension theory pans out, then we're only able to perceive 4 of the 11 dimensions we inhabit and that means we may come to detect a means to travel via at least one of those dimensions to where ever we want without having to worry about time and distance. We may be able to use gravitational lenses to enter another dimension and travel that way, or we may find some other means to do so.
Don't forget that human evolution has been rather late in the history of the Earth. Earth has had life for about 4.5 of its 5 billion years as a planet and has had at least two devastating extinctions where life essentially had to reboot nearly back to square one. What if other Earth like planets didn't suffer these misfortunes and life was allowed to evolve uninterrupted? Imagine humans being not just 200,000 years old but 3-4 billion years old. We can't imagine where we will be in 3-4 billion years or even what we'll look like but what technology might we have? Contemporary humans would appear to be no more advanced than chimps using branches to catch ants though already we have some technology which may be able to prevent the past disasters that caused the mass extinctions of Earth's past. 200,000 years to be able to deflect a possible asteroid isn't all that long. If other civilizations could advance to our point, and even if they were beset with the same problems of religion and competition, it's safe to wager that they would have developed similar technologies to prevent further mass extinctions. That would given them a truly uninterrupted period of techonological and evolutionary development literally spanning billions of years.
We may be alone, however this article states what most astronomers and exobiologists now believe; that we are now statistically certain that we are not alone even though it does not guarantee intelligent life. It does at least guarantee that there are extrasolar inhabitable planets out there for us to colonize and exploit or, if inhabited by intelligent life, contact.
