Taking other people's ideas and building on them is a foundation of human ingenuity. The same can be said of art. Great movements like Impressionism were not limited to one person. Monet didn't sue Renoir or Cezanne for 'copying his style'.

AI Art might scrape its data from billions of other artists' work but its not a direct copy of them, merely the style. I'm also not sure AI generated works will become that prevalent. Brands will always want to seem as authentic as possible and claiming they use human-created works will lend them credibility.