I don't know if things are getting worse, but I can give you some things to think about. I've been thinking about them.
The worst plague that I know of was the Black Plague, which was in the 1300's, and killed about 75 million people, undoubtedly one of the worst natural disasters, and the worst earthquake was in China in the 1500's and killed an estimated eight hundred thousand people.
As far a war deaths, World War 1 is ranked sixth, not first.
The Watchtower makes assertions, then gives no citations, names, etc. to back up their statements. So we believe them when they say things are worse. In history, things get worse, then things get better, then they are worse, etc.etc.
I was young, now I am old. Things are worse (so they seem) but much better in other, more concrete ways. Who can say?