Sure we have nuclear power, but at the risk of the president holding the ability to level most countries. The only difference I see is that the harms you describe from AGI are nebulous and non-specific.
But there's another component to that too: the ability to "level another nation" isn't quite a function of nuclear weaponry - it's much more a function of rocketry which makes ICBMs possible. It's perhaps an interesting thought exercise that a world without nuclear weapons could still have a very large scale build up of say, ICBM-delivered thermobaric weapons which would enable a country to rain effective destruction down on any other while being at no risk of being responded to in-kind.
Nukes short-circuited that: because it's much cheaper to put a nuke on an ICBM, and as such all ICBMs are presumed to be nuclear until proven otherwise, as a result now, no one uses ICBM technology to deliver anything but nuclear weapons since launching anything else invites a nuclear response (one of the big problems with most of the "carrier-killed" missile concepts - their launch sites look indistinguishable from nuclear ICBMs).
The threat of nuclear war hasn’t gone away you know ? There is as much chance now as ever before for a civilisation ending nuclear exchange to happen even if by accident.
This is real, not fantasy.
I stumbled on this recently: https://www.samharris.org/podcasts/essentials/making-sense-o..., I have to say it was fucking terrifying.
Summary the podcast: “we have forgotten about the situation we’re in…it’s as if 75 years ago we rigged our houses and buildings to explode, and then just got distracted”…it’s really with a listen.
Access to mining previously was cheap and available.