Fuses are available as 1A, 2A, 3A, 5A, 7A, 10A and 13A yet only 3A and
10A seem to be in common use.

I've been checking some fuses (when I got bored over Christmas!) and
many seem to be far higher than needed, most notably a printer fitted
with a 10A fuse when the rated current is 2.5A. I changed this to 5A
(to leave some headroom). The toaster does not need 13A; 7A is fine.
LED lamps do not require 3A. 1A seems fine.

I appreciate that the fuse is intended to protect the lead not the
appliance, but surely there is a side-effect of protecting the
appliance? Is there any benefit in fitting a fuse significantly
larger than needed? Common sense suggests go for maximum protection.

I appreciate that motors have a surge at the start. I believe a 50%
margin should be added generally (more for a motor).

When the ring main system was introduced (in 1947, I believe), the
correct fuse was used for each appliance. Why have we moved away from
this commonsense arrangement and apparently degraded a safety feature?