Those bods don't seem to like their "thermomagnetic breakers". In what
way do their breakers differ from our modern MCBs?

They have thermal trip only. They cost about 1.3p to make in some sweatshop
and are as reliable as a clingfilm condom.

The US electrical system is simply unsafe compared to the rest of the world.
It largely comes down to:

Lower voltage. 110V is much more dangerous than 230V. This isn't obvious to
the non-technical, but the US went with "common sense" (aka thick people's
prejudices) rather than sound scientific analysis. The basic issue is that
very few people die of electrocution, whilst loads of people die from
electrical fires. The electrical fires largely stem from high currents. If
you halve the voltage, you double the current.

The high voltage has other safety benefits, too. For example, during an
earth fault, the higher voltage leads to much higher current flow. An
overcurrent safety device is, thus, much more effective, leading to much
more rapid disconnect of the circuit.

Some numbers. Take a hypothetical circuit rated for a bit over 3kW. In the
US, this would be 110V, 30A. If the breaker requires 5x current to trip
immediately, this requires an earth impedence of 0.73 ohm right back to the
substation. Of course, most US circuit breakers are thermal anyway, so trip
is never immediate. With less than about 0.73 ohm, it will take much longer
to trip (or perhaps it never trips, if the earth loop impedence is too
high). A slightly higher energy circuit in the UK would be 230V, 15A. The
required earth impedence is now 3.8 ohms. This is extremely easy to achieve,
unlike the 0.73 ohm, which might even be impossible.

Another effect of the low voltage is that "respect" for electricity is
lower. The lower voltage leads to lower quality insulation on fittings,
cheaper parts and a blase attitude of users to electrocution. The result of
this is that the US actually has a higher electrocution death rate per
capita than the UK, despite the lower voltage! When you compare the
incidence of electrical fires, the differences become much more scary.

Other differences in the US:

1. Low quality cables that have arcing failure modes, leading to fires.
2. Use of wirenuts.
3. Combination of neutral to earth (i.e. effectively TN-C earthing) leading
to electrocution in the event of polarisation swap, or some open circuit
conditions. TN-C earthing in banned in Europe, except in special
(non-domestic) cases.
4. Provision of socket outlets in bathrooms, so users dry their hair in the
bath.

Christian.