Phil W Lee wrote:

Our BS1363 fused plugs (and the sockets to match) are a masterpiece of
design,

As area denial weapons they have few equals, it is true.

As plugs they have a couple of issues. As I understand it
the use of square pins requires a much higher contact force,
which in turn means that it's much harder to pull the plug
out, which
1) makes life more difficult for the elderly and / or arthritic
2) makes it more likely that the cable will pull out of the plug
rather than the plug out of the socket.

In the second case, this has the effect that if the plug is
badly wired, then the earth pulls out first rather than last.
And then has a good chance of making contact with one of the
others.

A good design would take into account lazy and / or incompetent
rewiring. It's no good saying "users ought to do this or that".
They won't.