the fact that the EPA told people "it was safe to return to their homes" was sooo crazy to me as an outside observer... damn America is fucked.

The fact alone, that these companies are allowed to transport reactive chemicals, that interact with another in really harmful ways, all on the same train, is crazy to me.
That's like telling people to use acid and chlorine cleaner right after the other...

ok, it is all underground here anyways, risks of fibers ever getting damaged like that is down 0.
Even my parents home/village has P2P all the way.

I am not sure but a PON-Splitter is almost certainly more expensive than say blowing in 12 fibers over 300m instead of 2.
I have not seen PON deployed here anymore since at least ~2 years.
Fiber itself is so cheap, my 9 flat unit just has a patch box in the basement with 12 fibers, and that's it. they do not even care to match them actual demand, 12, 24, 48 is what they do here...

https://imgur.com/a/PrnX8VA that's how it looked in my buildings basement when they first hooked the panel up.

PON also has higher risk of branch failures induced by bad customer equipment and since customer can use their own equipment here, by law, PON might be problematic for the whole PON-splitted branch.

FTTH is not FTTP, at least here. FTTP bundles, FTTB and FTTH PON/AON split in basement (which are not considered FTTH here).
But it seem to differ by region/country and even ISP.
Since about ~2 years now all the new deployments in my region are true P2P FTTH connection, with neither active nor passive splitting in buildings/premises...

One could also say FTTH is is a specific FTTP subset.... at least in our case here.

There is no practical reason not to do P2P FTTH anymore.
Unless you fear competition/regulation which is when GPON might be acceptable, still FTTH though.

The rest ist shit, expensive, crap.

People are dumb, and sellers/manufacturers cut corners all the time.

You need a good BMS too, the issues mostly arises from cells being overcharged because single cells are broken and not taking a charge anymore.
With NiCad and NiMH cells the batteries would just get warm and eventually the charger would hit a time or temperature limit.
With Lithium cells the charger or BMS have to detect this condition and stop the charge.
Most lithium cells will start breaking down very quickly once they are being overcharged, which is often resulting in fires.
On the other hand, fires of cars and such are also not really uncommon but often happen outside and cars also do not scale well in high density areas but eBikes eventually will.
What worsens the whole situation is the inconsequential regulation or the lack there of, of eBikes which prevents bigger players from entering the market and creating a common quality level.
Looking at Europe and Japan far over 90% of the eBikes are big brands which could never tolerate such failures in their product lines.

It is more of a general biozide that vertebrates seem to cope quite well with, yeah.
Less of a specific antibiotic or fungizide.