>If you make gigantic claims about some terrible disaster that might happen then I think you have the onus to give even one plausible explanation of how.

Supposing I warned in 2015 that the world is awfully vulnerable to pandemics. You're not going to take me seriously until I try to predict in advance every aspect of how a pandemic like COVID-19 would unfold? Why? What would that achieve exactly?

You haven't given any strong reason to believe wiping out humanity would be difficult. Your big argument seems to be that you couldn't think of a plausible scenario, in two minutes. But many major historical events occurred which weren't necessarily possible to anticipate with two minutes of thinking.