The difference is it costs billions of dollars to run a company manufacturing printers and it’s easy for law enforcement to pressure them into not printing money.
It costs nothing to produce an AI image, you can run this stuff on a cheap gaming PC or laptop.
And you can do it with open source software. If the software has restrictions on creating abusive material, you can find a fork with that feature disabled. If it has stenography, you can find one with that disabled too.
You can tag an image to prove a certain person (or camera) took a photo. You can’t stop people from removing that.