[yanderekko]

You can find discussions on this by googling "AI Foom" - the key idea is that an AGI that can recursively self-improve will be able to rapidly escape human control before any entity could check it, and very likely without humans even knowing that this had happened. Such an AI would likely consider humans an obstacle to its objectives, and would develop some sort of capacity to quickly destroy the world. Popular hypothesized mechanisms for doing so involve creating nanomachines or highly-lethal viruses.

That's key to the story of the paperclip maximizer - the paperclip maximizer will go about its task by trying to improve itself to be able to best solve the problem, and once it's improved enough it will decide that paperclips would be maximized by destroying humanity and would come up with a plan to achieve this outcome. However, humans may not realize that the AI is planning this until it's too late.