Lem wrote:

Are surge protectors on the main power supply actually needed in
the UK?

here in the UK we have few overhead mains power lines and have a
relatively steady mains power supply when compared to many other
countries (including the US).

However there seem to be very many surge protector products
advertised for sale in the UK (Argos, Maplins, etc).

I am quite sure it is not bad practice to use a surge protector but
in fact I have never known anyone who has has a problem from a
surge coming in through the power supply.

So personally I don't bother using a surge protector on my PC.

Am I being too complacent?

Definitely good to have one as an insurance. Heavy machinery can induce
start currents and outages can result in spikes. Also heavy crossposting
can overload the system.