https://en.wikipedia.org/wiki/Hyperoxia
This was a screenshot I took months ago while watching a Geology Hub upload on YT. It was a lightbulb moment for my understanding of mass extinction events, (the largest was 250ma). I’ve referenced this multiple times, so thought I might share. Perhaps you find it as interesting as I do.
We are merely the space ships of the microbes. Being caught between their war of the worlds would likely be unpleasant. However, I have a feeling we would be the true harbinger of death in that world of far more simple food webs than our present reality.
Our deaths would be miserable upon return, due to the evolutionary life of our passengers having many millions of years to plot our deaths when we return to find a completely different world and the little ones waiting to say hello.
I do not believe the table is intended for individual timescales, like how I tried to make the title more relatable. It is intended on geological timescales of species survival.
IIRC the person on YT also mentioned there were times when there was not enough oxygen to sustain fire, which is another fascinating thought and helps make sense of things like hydrocarbon deposits like oil and coal in some instances.