Lithium batteries are much more energetic about their failures, "explode", and they can do so with only minor electrical or mechanical mistreatment.
A car in my garage is cold, outside of very odd situations it is not going to spontaneously ignite. Cars burn in accidents or when you are running them, not randomly in the middle of the night.
The "proper" safety for a large lithium battery pack is in a concrete sarcophagus or similar vessel capable of shielding and containing a catastrophic failure.
My co-worker's nanny's car, a new Subaru, burst into flames in her driveway while it was just sitting without the engine running. Non-crash fires occur so frequently that the Highway Loss Data Institute (HLDI) produces a Noncrash Fire Losses Report, and insurance companies calculate premiums based on that data.
https://www.iihs.org/media/c93b98d8-6a7d-44a1-810e-4468ec539...
I'd have a power wall either in my garage or in a box outside the house if it would mean that we could go off-grid. Sadly that's not possible here (we've got more wind power than sun power and residential wind isn't feasible).
Not only that, but they are actually no more energetic than gasoline. This is an example: https://www.youtube.com/watch?v=CdaFk3w6rUY
Gasoline actually has a higher risk of becoming "explosive", though as you pointed out that is not the most common outcome.