An image of an archeologist adventurer who wears a hat and uses a bullwhip

If infringement is happening, it arguably doesn't happen when an infringing work product is generated (or regurgitated, or whatever you want to call it.) Much less when the model is trained. It's when the output is used commercially -- by a human -- that the liability should rightfully attach.

And it should attach to the human, not the tool.

It isn’t an independent human. It is a service paid for by customers. The moment it provides the image to a paying user, the image has thus been used commercially.

In fact, the user may not even necessarily have to be paying in order to infringe copyright.

And besides, even amateur artists are ashamed to produce copies unless they are demonstrating mastery of technique or expressing adoration. And if it happens spontaneously, they are then frustrated and try to defend themselves by claiming to never have even experienced the original material. (As happens with simplistic, but popular musical riffs.) But AI explicitly is trained on every material it can get its hands on and so cannot make such a defense.

If you do it for free, is it different?

If I ask a friend to draw me as Indiana Jones? Or pay an artist? In either case I just want that picture to put in my rec room, not to sell.

Private copying and transference, even once for a friend, is copyright infringement.

I don’t necessarily agree with this, but it is true nonetheless.

Not without money or equivalent trade involved.

I can draw Mickey Mouse all day on my notebook, and hand it to you; no legal issues.

If I charge you a pack of bubble gum - Disney's lawyers will kick my door down and serve me notice.