I am a long term optimist.
Humanity has been improving our condition for 12,000 years on an exponential curve, with breakthroughs and revolutions happening over and over, and there is no reason to think that trend will stop. Up ahead we may well see major breakthroughs with AI, nanotech, bioengineering, fusion power, moving into space, etc. Even as we trip up (toxic chemicals of the 50s and 60s, chernobyl disaster, obesity epidemic currently, climate change, etc) we eventually innovate our way out of these problems. I only wish I could live to see the great breakthroughs 100 years hence.