Agree, gotta reach at least 20% O to have an ignition via either abiotic or biotic means. Venus is a great example. 

Latest research points to both been a lot more rare than what we once thought. Very interesting distinction between life (no fire) and civilized life (barbecue 😎).

Balbi, Amedeo, and Adam Frank. “The Oxygen Bottleneck for Technospheres.” arXiv preprint arXiv:2308.01160 (2023).