Right, though the evolution of photosynthesis in early anaerobic microorganisms and then their ability to adapt to the oxygen they produced is quite amazing. Oxygen itself is also really fascinating when talking about life because its oxidizing power accelerates the life that makes use of it.

As many experienced gardeners with compost piles know, anaerobic decomposition is much slower and messier than aerobic. Regularly turning the compost pile helps aerate it and makes the aerobic decomposers thrive.

Because molecular oxygen is a highly reactive species, it would also rapidly deplete.

And its reactivity is what makes it so useful for powering advanced life. It's an abundant and highly energetic fuel.

The fossil fuels that gave rise to our industry and innovation are also something we lucked into. The right decomposition environment, eg. in the Carboniferous, made these massive deposits possible. This has greatly accelerated our innovation as a species.