Earth nearly lost all its oxygen 2.3 billion years ago

"Cyanobacteria began producing oxygen, which reacted with the methane in the atmosphere at the time, leaving only carbon dioxide behind."

The mythical GOE requires that the early cyanobacterial oxygen be rapidly sequestered by dissolved ferrous iron in the oceans to keep the Earth's atmosphere anoxic or very low. That early oxidized iron is permanent...the banded iron formations. There should have been no oxygen left to react with methane. The only thing left behind would be the organic carbon from cyanobacteria...and that doesn't exist. Indeed, without aerobic recycling of the cyanobacterial organic matter there should be huge amounts of organic matter preserved from the very beginning. The cyanobacterial oxygen cannot be used twice. Once to oxidize iron and then again to oxidize the organic carbon. The GOE hypothesis is not confirmed. nor is this current theory. about late oxygen loss.