Failure rates for automotive Li batteries are quite low. In the range of 0.001 per 100K vehicles.

I'm aware, and compressed gas storage containers are equally low if not lower. They also fail in a way that is safer than batteries fail. The tanks are engineered to split and the limited, usually zero, shrapnel is redirected downward.

What really limits compressed air as a vehicle energy store is the inability to reasonably run climate control off of it.

And the incredibly low round trip efficiency - heat production then loss to the environment as part of compression is pretty brutal on that front.