GB wrote:

I cannot think of any cases where it is worth bringing a defamation action.
Ever.

The damages are never worth the effort. The publicity from the case can be
worse than the original defamation.

There are some instances where it may be worthwhile. For example in
New Zealand a radio personality said on air that the Prime Minister's
son had been busted by the police for drugs. There was not a grain of
truth in the statement. Daddy made sure the son sued and he got an out
of court settlement and the personality's scalp. As a staff member of
the broadcaster said to me privately, what can you do in such cases but
sack the person and settle the best you can.

There are cases where the defamation may be so gross (ie completely
false and harmful) as to cause serious potential harm to the person
defamed, that there may almost be no option for the victim to sue, or
at least to take some form of legal action even if it is merely to seek
a retraction, apology and a donation to charity.