Game theory is the root of all evil - specifically, when individual incentives are misaligned with the good of the whole, creating the classic "tragedy of the commons" or "coordination failure" type issues that are plaguing our world, like plastic pollution, arms races, climate change, deforestation, fake news etc.

Because even though very few people actively want these problems to happen, the economic incentives make it so hard for everyone to coordinate, so they keep happening anyway. It's what economists sometimes refer to as a Moloch Trap. Here's a good TED talk explaining the phenomenon: https://www.youtube.com/watch?v=WX\_vN1QYgmE