Nobody has been able to make a convincing argument in favour of generative AI. Sure, it's a tool for creating art. It abstracts the art making process away so that the barrier to entry is low enough that anyone can use it regardless of skill. A lot of people have used these arguments to argue for these tools, and some artists argue that because it takes no skill it is bad. I think that's beside the point. These models have been trained on data that is, in my opinion, both unethical and unlawful. They have not been able to conclusively demonstrate that the data was acquired and used in line with copyright law. That leads to the second, more powerful argument: they are using the labour of artists without any form of compensation, recognition, permission, or credit.
If, somehow, the tools could come up with their own styles and ideas then it should be perfectly fine to use them. But until that happens (it won't, nobody will see unintended changes in AI as anything other than mistakes because it has no demonstrable intent) use of a generative AI should be seen as plagiarism or copyright infringement.
Parental consent is usually used as a substitute where a child is too young to give consent for a procedure. In Australia and the UK once a child is able to understand the procedure and associated risks they are considered "Gillick competent" and their consent outweighs the parent's, but until then the parent is the one who gives consent on the child's behalf. Parental consent is also used as a substitute when the child is incapacitated by injury or illness such that they are incapable of giving informed consent. Health practitioners and first aiders can also assume consent in life-threatening situations where the patient is incapable of giving consent (e.g. giving CPR to someone in cardiac arrest).