Nonconsensual porn laws generally aren't restricted to commercial use, and some include fake images with intentional and recognizable use of likeness (some also don't, its a mixed bag.)
Yes, commercial use of likeness is also an issue, and it may or may not be violated simply by distribution of something use the likeness on a commercial website like civitai.
Right now CivitAI is basically Stable Diffusion social media. It doesn't seem profitable at all, even of they are selling user data or getting subs or whatever.
But if they start charging for downloads or whatever, they may cross a line into making money off likeness, and not just "hosting user content" like Facebook and Twitter and any oldschool image hosting service gets to say they do.
How can that possibly be enforced though? You can't really stop people from drawing or photoshopping stuff for personal use, and this is essentially a further extension of the technology.
The fact that a small problem exists does not negate the existence of a larger problem.