Yeah, like it's not that long. They should add that disclaimer to the safety messages at the beginning of the flight. "In case of an emergency, you will have 12 minutes of oxygen, which while we know is not that much, is better than to die instantly."
There is a cloudberg article on a crash due to faulty/expired oxygen generators in cargo. They use an exothermic reaction that produces oxygen. But of a fire hazard. I suppose there is a trade off of how much oxygen vs. fire risk.
