The problem with that is... humanity is doing a good enough job of messing things up without AGI. So if AGI was delayed by such, there's a non-zero chance humanity fails to create AGI or survive in the new timeline.
Between the Earth's climate/environment being wrecked (we're well into some of the pessimistic projections for the 2050's) and SARS being allowed to run unchecked playing Russian Roulette with peoples' health (including literal brain damage), we're going to need a miracle.
Outside of AI x-risk, there's very little chance that any of these scenarii (short of an asteroid) would eradicate mankind. There's just so many of us, in so many places.
Even total nuclear war would, based on the Fermi estimates I've seen, not be able to do it.
We can agree that things are not all rosy, but picturing as "so bad we might all disappear" is a bit far-fetched.
Between the Earth's climate/environment being wrecked (we're well into some of the pessimistic projections for the 2050's) and SARS being allowed to run unchecked playing Russian Roulette with peoples' health (including literal brain damage), we're going to need a miracle.