I can see Midjourney already replacing the low end. The question is how good can it get, and then as the bar is raised what can be done to differentiate. Answer to the latter ironically may be going back to old school human interfaces.
There is a grain of truth to this, but again just choose whatever lower-budget website you want. And then just try the exercise I suggested.
Midjourney isn't producing work at a "bad Fiverr" quality level, it's not producing usable work at all yet (at least without a lot of hands-on prompt tuning, at which point why not just use Fiverr?). At least with Fiverr, I am likely to end up with something I can put on the site, which is not true of Midjourney yet.
Decent in this context doesn't mean something I could just hand to an editor. But it does mean a pretty good starting point that I could amend, flesh out, add some links, add a quote or two. I could certainly see using it to give me a sort of pre-draft on some fairly evergreen topic.
I could also use it to generate some boilerplate definitions or historical background to include in an article.
But, sadly, I think you'll see the LLMs being used to generate a lot of blog/article content with a minimum of human effort for even less than the small amount being paid for a lot of this today.