I disagree that they have more failure points than ICE. They are fundamentally simpler. I have many years-old lithium power tool batteries that are beat to crap....dropped....frozen....cooked....and still work just fine. In comparison, my various ICE vehicles and other small engines have needed gaskets/seals, idler bearings, sensors, oil changes, etc. If my M18 drill was powered by let's say a model airplane engine instead of a 5 amp-hour lithium ion battery, it would have doubtlessly been less reliable.
I totally agree on the fire and overall hazard potential of lithium batteries, however, and I'm glad our hybrid has a NIMH battery instead. Lithium is highly reactive and emits dangerous fumes when it burns and it can't easily be put out, in addition to exposing first responders to the toxic chemicals. It's one of the dark sides of EVs that folks like to forget about.