It's true that Lithium Ion battery fires are harder to deal with but this can be mitigated by having the appropriate suppression material.

As far as i know, there is none.

LiIon once started, will burn, even underwater.

And yes, it is because of cheap Chinese quality, but these batteries do not have much tolerance. Large LiIon batteries will always catch on fire. It is why the Tesla has hundreds of little batteries.

And this is just the battery, we haven't talked much about the deadly electrical shock potential.