I kind of agree with this. We've done alot scientifically but via science we have also ruined alot. For example cars, planes, trains etc are all great but they cause pollution. We disrupt most ecosystems with things like deforestation and then decide we need to cull certain animal types, which leads to executing other animal types to retain a balance. If we didnt screw with nature and ruin the balance we wouldnt have so many problems now.humans created airplanes and skyscrapers and many other wonderful pieces of engineering. What birds can do naturally we worked our socks off to do artificially, and succeeded!!
However being the most intelligent species on earth, we also brought death and destruction on a never before seen scale. We are the only species to take another living being's life "just for fun". We have also destroyed our planet with such things as airplanes and cars and industrialisation.
So, a world without humans! Let me think, a very boring world free of aircraft, Empire State buildings and Great Walls across China. A world free of comedians, doctors and lawyers. However this boring world would also be free of:
* the Holocaust
* The M8 (replace with your nearest motorway) on a Monday morning!
So what have humans really done for the world?