Photography didn't replace painted art.
Digital art didn't replace traditional art.
3d art didn't replace hand drawn art.
Why is AI going to replace anything?
I think that idea is based on a proposition "AI generated images will replace all other type of images" which is not true.
It's just another tool that will be used among others, some people will use it, some people won't, some people will use as a mixed media utility.
The existence of one thing doesn't invalidate or harm the existence of another. As in many aspects of life most things can coexist together.
I visit some image boards which are media neutral, this meaning they don't discriminate by media. Most art there used to be digital painted or 3d, and now there is AI art but it hasn't replaced anything. Digital and 3d art are posted at the same rate, now there is just more art in the form of AI generated art. It didn't replace the other artists, it just added to them. Now there's more content for people to enjoy, everyone wins.