I think this is like asking: will the word processor affect clerical services?
Yes, and no. Yes, AI can perform tasks in seconds, so, yes, it will impact writers. No, it isn't necessarily something to fear if you embrace it. Just imagine the volume of quality content can be created at speed, if you use AI to create first drafts. As a writer, you can use your skills to perfect the rather dull and mechanical output from ChatGPT and all the others. AI cannot, at present, write with your unique voice - this is for you to do.
Ultimately, I suspect AI will be one of those incredibly useful tools - like someone sitting next to you saying - here are my ideas - now go away and express them in your own way.
But maybe I'm seeing the glass half full.