Lots of quotables. Your research is solid. But cyano-bacteria didn’t evolve to become nicer. Other species evolved to exploit the new oxygen and cyano-bacteria rich environment. The cyano-bacteria ran out of abundant fuel, disliked the colder world they caused and became surrounded by their own poisons, and retired to favourable niches.

Previous mass extinctions, since the oxygen catastrophe, were not as fast paced as we have triggered. All associated with greenhouse conditions. Ocean heating brought about low oxygen production. In the previous record extinction biggie, the Permian-Triassic, 90% of all species eliminated.

Bigger proto-mammal species were wiped.

Atmosphere O2 got down to about 11%, half of what we are adapted to. Birds are dinosaurs that evolved even better lungs than ours.

Fortunate for our big Fossil Fools Party, for the next world system rebalance and evolution reset.we are rapidly running out of economic accessible resources including Oil and critical minerals. Global Economic Collapse cannot happen too soon. We are also not adapted to a hot, low oxygen world.

So humans are running out of resource, options, surrounded their own poisons, and won’t be able to breath, let alone reproduce – Human Reproductive health has already much declined. By the next hot house earth, the last of the apes species will be extinct, just like the last bunch of extinct large mammalian species before the dinosaurs. Unless we undergo drastic genetic and behavioural engineering, like acquiring bird lungs, maybe eyes too, in which case we will be no longer “human”.