It reminds me of a comment I once read about how alien visitors, upon arriving on Earth, would be appalled to see how we live our lives at the bottom of a giant gaseous ocean of 20% oxygen.

Almost everyone and everything around us of any importance is one mishap away from going disappearing in a hot, sooty flame.

For another perspective on this, see the book Shroud (https://en.wikipedia.org/wiki/Shroud_(Tchaikovsky_novel)), there is all sorts of nifty commentary on oxygen related to your point.

(it's a great book in general, but the bit about our use of a volatile gas for a living environment is pretty neat)