While the ability to distinguish the two may shrink as the tech grows (if it even gets the chance) the chances of it replacing human workers as it is is still slim to none.
People and especially companies and organizations looking to avoid having to spend money on human workers may turn to using these things but folks who understand and respect the process that goes into art or writing will remain loyal to human artists and other creators
As to how this stuff works for novels or any other kind of writing I'm honestly not sure and even for stuff that seems readable I've heard more talk about how a lot of the writing is still kinda nonsense
In terms of fights against the machine it's both a matter of ethical violations and copyright violations since a lot of the material these things work from are stolen from artists and writers so it's a bfd. The biggest pushes against them are the ones spearheaded by big companies like Getty butt there's already been a big cut to prompters (so called ai "artists") stating clearly by governing bodies that they cannot claim copyright over anything produced by an ai generator since it's not made by a human (i can't recall the specific case but it's pretty easy to search up)
and as I mentioned above the ability to distinguish them now tends to fall on small details like how the hair falls, hands, clipping of materials and so on. But lots of folks warn that this line may be blurred as the tech grows and changes over time. Even still theirs going to be some kind off flaw in it but it may take more time to analyze which is why people are pushing for platforms and companies to take a stronger stand against the use of them but it's...not so 50/50 right now since some people care but a lot don't since "ohh pretty pictures and easy access writing and fast money ahhh"
There's like...no reason to be jealous of something made by folks not even willing ot put the time in to honing a craft tho coz at the end of the day even if the results seems.. good(?) it's just a cheap shortcut (and not in the actual artists/writers finding ways to make their process easier or simpler) but in the it's a quick jump from point a to point z without any actual labor or effort (which is cheap and lazy)