I'd be a bit frightened if I knew someone in my apartment building was assembling their own batteries -- poor quality ones can burn down the building.
It's an increasing problem here in San Francisco. I know at least one friend who had to move due to smoke damage caused by a neighbor collecting these batteries. https://sfstandard.com/2024/01/09/san-francisco-e-scooter-bi...
Doing anything with mains power, water pipes and gas pipes is still done by many people themselves, and the risk is minimal.
Also most of the battery fires happened with factory installed batteries, be it in vapes, galaxy notes, or other devices.
The rate of proliferation of gadgets with such batteries is crazy. So much of society already has so many of these little flashpoints in phones, tablets, toothbrushes, kids toys (electric scooter anyone?) - statistically your concerns are already valid without anyone being an electronics hobbyist.
So can galaxy notes, hoverboards, vapes, etc. So can poor electical installations, bridged fuses, cooking oil fires, etc.
These packs (18650 based) are a lot safer than "baggied" packs found in many fpv drones and RC cars, and those packs are factory assembled.
Firewise, i'm more afraid of an alcoholic with a cigarette, than of batteries.