It’s actually surprisingly hard to get a lithium cell to catch on fire from simply physical damage. You need to break it very specifically, and crushing them flat with a fucking tank will just shatter them before anything serious happens.

The reason that it happens so much due to damage is because there are a LOT off cells, and if someone damages the pack, there’s a point between total destruction and no damage where it’s just the right level of damage to cause thermal runaway reaction. The other reasons are manufacturing defects, and shitty charging, which are WAY more common than physical damage.