Intelligence is not a hypothetical, we spend 100s of billions per year protecting against other human intelligences. 30 years ago how much were you spending on computer security? Yet somehow computers are supposed to get more capable and you expect us to do the same amount as now.
Like dude, it didn't happen because a lot of people prevented it, the same with nuclear war.
Because something could have tragic consequences is a reason to put great effort into ensuring it doesn't happen.