Economic collapse?
Another "virus"?
Nuke/War?
World domination. The same old dream. Our asylums are full of people who think they're Napoleon. Or God.
It will be another virus or drug resistant bacteria. Either way they have treatments they won’t speak about.
,,, I’d pick economic collapse. It happened in 2008. Flooding the world with $US has caused over valued housing and stocks prices and notably devalued the currency. As many say, the problem’s been kicked down the road. US debt is being dumped and tussles in the Asia Pacific and other regions are going to cost a whole lot more - and they’re going to happen.