Let's assume you didn't have a pre-existing knowledge of "what are real, reputable journals for scientific research"? (As opposed to being in a "real world" community where that's institutional knowledge, where you would be looking to curate your internet usage instead of trusting the full public one).
How far away do you think we are from some being able to auto-generate entire fake journals, with plausible-sounding and -looking fake text, fake images, etc, pushing pre-specified prompted conclusions. Maybe mix in some real plagiarized articles as well in tangential areas.
And then you auto-generate a bunch of blogs, that occasionally have some posts talking about how JoesFakeJournal is just as reputable as JSTOR, etc, and actually better because [some random, probably fake, controversial claim]. Or how it's even better for certain topics.
And then auto-generate a bunch of other blogs which occasionally have posts claiming that the legitimate ones are actually fraudulent.
How big of a web of this sort would need to be faked before you, the outsider without special inside-baseball knowledge of academic publishing, would struggle to tell which journals you could trust from which you couldn't?
EDIT: And could a clever enough spammer not just brute-force the creation of all that crap, but figure out how to use prompts to get the language models to create the necessary follow-up prompts, etc, to recursively build out the web of bullshit?