Work out the details on exactly how said end-of-the-world would occur.
Note that we already have “AI to end cities” - they’re just sitting, turned off, waiting for the code and button press in silos and submarines throughout the world.
The danger is from something vastly more intelligent than humans, and with a mindset that's incomprehensibly alien. No human is capable of working out the details. That doesn't mean the risk doesn't exist. Failure to understand chemistry does not make ants immune to insecticides. The only thing we can assume about a super-intelligence is that it will be highly capable of achieving its goals. There is no reason to assume those goals will be compatible with human existence.
Note that we already have “AI to end cities” - they’re just sitting, turned off, waiting for the code and button press in silos and submarines throughout the world.