There is much that is terrible in what we have done, but
there is also much that is amazing.
200 years ago, the idea that humans could fly was
"impossible"; 100 years ago, the idea that humans could walk on the
surface of the moon was "impossible"; 50 years ago, the idea that you
could carry your entire music collection or library around in your pocket was
"impossible".
Never assume that anything cannot be done or cannot exist.As a species, we have been on the Earth for the blink of an eye, relatively speaking. And yet, look at all that we have achieved in that fraction of time - both bad and good, and there is plenty of both.
There may be other civilisations beyond our solar-system that have achieved far more (I find it highly unlikely that there are not), but we do not KNOW that - yet.
For good or ill, we are the dominant species on this planet;
and we are a remarkable one!