I’m guessing you’ve looked at the stats for vehicle fires though - quite dangerous travelling in a ICE powered vehicle when you think about it
IIRC these stats are potentially skewed though. They're not based on the vehicle itself catching fire - they include arson etc. and fires from cargo or onboard equipment like refrigeration units (which are often left running at all times, even when parked). As you know the huge majority of goods vehicles are ICE powered. It may indeed be that EVs are a lower fire risk, but I don't think there are any reliable statistics to support this.
The majority of EVs are also quite young (bearing in mind that almost 50% of the cars on UK roads are over 10 years old). We won't know for a few years yet whether older EVs might see a higher incidence of fires (as battery packs age etc.).