Once a reader has validated a writer (you like the style, the context helps you and proved to have high value), your attachment to the author is even higher than before, because the cost of finding anything else of equal quality is skyrocketing.
I've been given a lot of attention to find the right fruit and vegetable provider for years since we have abundance but most of it taste like crap. I'm extremely loyal to the farmers I buy from, and I buy at a premium from them. Despite the fact I'm always trying to find new ones, it's very rare I do.
It will be the same with writers.
Even if GPT starts to include my articles in it's training data set, I can still provide a lot of value with tooling, contextualization, integration, coming up with something new, etc.
To me, GPT is only making my work shine even more. And it helps me tremendously when I code, so I just love it.
But this will change in the future, so I would say those are temporary advantages for us only.