Is AI always worse than human authors?

I write a bit myself, though not very attached to the craft. So, looking at AI stuff, it's always people in creative fields that condemn the technology. Obviously, it's due to competition, but competition needs you to be 'out-competed' in a way.

I've seen numerous authors alike reffer to AI written stories as slop (I personally don't like them very much either), but if their stories were better by default (and I'm not talking about the 'soul-argument', but rather actual written quality from the prose to plot tightness and character development), then why are authors struggling more?

(I'm aware writing has never been easy, and lots of people have failed even before AI, but I really want to talk about this new factor.)

People argue that AI gives them a struggle for multiple reasons, from it's relentless volume of production, to flooding the markets and muddying visibility. I won't deny that. But if human stories were always better, then no one should be buying those AI books.

Most of the time AI books aren't cheaper than human ones, so using the 'slop' analogy-- consumers should almost always pick the human stories, and the AI ones should've been buried by human books, similar to the trouves of forgotten 60's pulp crushed by just better authors.

But if people still pick enough AI books to undermine human authors, (enough for this to be cried as a problem), then are casual readers just hooked on something I'm not aware of?

In conclusion, my question is: If an author's struggling due to AI, is the AI performing better simply because it is in some ways? Or casual readers, are just skipping out on them for its own sake?