Sandy wrote in message:

The term "living trade" is just a parallel with "living language"
Any language which is spoken by living humans evolves and changes.
The opposite is a "dead language" such as Latin which is static and
does not evolve or change.
Similarly for "living trade". I'll let others think of "dead trades".

In the context of terminologies, you might well assume a parallel by
definition of that which evolves and changes...but, what is your
point?
Stupidly, I have been accused of inventing the term living trade in
arcanum...oops, there's a dead language; when, in fact, the phrase is
merely common language usage, to describe a parameter for discussion.
Are you entering into this discussion, or are you one of Conan's
pointy-headed friends? Perhaps, you will elaborate on what others
think of dead trades...