Some people are puzzled by this: I am a writer, yet I still get books aimed at new writers like ones about plot structure, or creating characters, or on dialogue, and so on.
Some books just make sense; I’m self-publishing on the Kindle, so I’m reading many books about that. In a few months, I won’t anymore.
The books about writing techniques also make some sense. First: any writer who thinks that there’s nothing more to learn is just fooling themselves. You can master what you’ve already learned, but there may be new approaches to elements that you’re not yet aware of.
This too will hopefully be soon done, however!
I believe it only makes sense to continue to get and read writing books, no matter how long you’ve been writing. There’s always something new to learn, and even if many of the techniques are ones that you’re familiar with, looking at them from the viewpoint of another writer may light a new spark in the way you write.
I find that reading other writers tends to give me more new independent ideas ofmy own (and that can be a dangerous and beautiful thing 😉 )