Fair enough, if you suppose the wheel and fire, and antibiotics had a genuine potential to end humanity.

The atomic bomb did, of course, but only down one primary path: a human firing them off

I’d argue the internet is probably the closest, as the doomsday branches it (global connection and instant worldwide communication) might lead down are much more complex and numerous.

From the perspective of the humans who first harnessed fire, it could have been a humanity-ending threat for all they knew. Certainly for the atomic bomb, they briefly entertained the possibility it would literally ignite the entire atmosphere.

And under a long enough time horizon, you could just as well argue that pretty much every scientific advancement has contributed to the development of modern AI. Does it count as AI doom if a century from now humans just start a plain old World War N with barely-intelligent killer robots?