Electric buses are now cheaper than diesel/CNG
electrek.co
electrek.co
They are heavy and stop and go a lot, which is ideal for regen as they slow, and electric motor torque as they pull off again.
They run standard routes, which lets them plan refuelling with some certainty.
They're used heavily, which means low fuel costs and low maintenance costs add up faster.
They're owned by businesses that are happy to invest up front if they can calculate that the above will break even within a certain timeframe and start to pay off.
They're used in city centers where pollution is a hot topic, with diesel being banned by cities etc.
The Proterra buses (company quoted in the original link) look to have 1000s of pounds of battery in a bus. Judging by the ferocity of a laptop/phone battery burning if the bus' batteries could be maliciously burned it would be an absolute inferno.
If we are talking malicious, releasing any combustible gas in an enclosed area can cause a building levelling explosion.
As a culture, we have gotten used to life with super combustible stuff. Batteries might actually be a significant improvement.