I live in the U.S. and I believe perception is reality.
It really comes down to how well the individual is doing in their own life along with how much they expose themselves to all the negative things going on in the world.
There has never been a time in our history where there were absolutely no atrocities taking place in the world. We just didn't have 24 hour cable news stations, the Internet, and social media to instantly get the word out or beating us over the head with it.
There are children playing right now at Disneyland who will look back fondly on (this time) as being among the best time of their life!
Maybe ignorance really is bliss!
This may also explain why meditation, exercise, and healthy lifestyle choices are touted as contributing towards our outlook on life.
Happy people are positive about the future! While one person may be dealing with unemployment, medical crisis, victimization of crime, concerned about future wars, or losing sleep over a million things... It's only natural for them to be pessimistic about the world.
There are also people in this same era who are enjoying life!
It's always been that way and always will be that way.
Life is a (personal) journey.