Fires are generally caused by loose connections with higher resistance getting hot and catching something nearby on fire. The British connection in OP is much less likely to have a loose connection.
So 230V stops it does not sound right. Whether there is any difference in probability I have no clue.
Typically the distinction is made between 50 and 60 Hertz, where 60Hz is typically considered safer(though I’m not sure if this is even true).
I am an electrician hence why I am curious.
The problem is that the risk of death is so low for both that people's perceptions are skewed. Everybody has been shocked by their household voltage a bunch of times, so they think it's no big deal. Until it isn't.