Again, thanks to everyone involved in bringing this back...
That said....
Very little in copywriting doesn't stand the test of time. That's what make it an evergreen skill.
But IMO opinion, some of this just doesn't apply in today's marketing. I'm open to being wrong but for me content is more important the structure of your newsletter. YMMV, but subscribe to Tony Shepherd and then think about it.
Yepp copywriting is definitely an evergreen skill because it's much more than just putting words on paper... it really boils down to human psychology.
And that's really what makes it an evergreen skill, because human psychology hasn't change and will not change for as long as we are all alive.
So if you become decent at copywriting, you will become decent at human psychology... and if you can become decent at human pscyhology, well... you can pretty much create for yourself whatever sized paycheck you want, even if technology changes everything and even in uncertain times with an economy gone to hell.
RE: your observation about content being more important than structure...
Sure. Bad content put into the right structure won't yield the same results as good content put into the wrong structure.
But you can most definitely boost your results by putting good content into the right structure.