I haven't been responding to most of the responses I get here, but I do want to tackle this one. Because I do think this is a pretty big misunderstanding of the situation.
So, I've characterized the use of AI in a classroom setting as a failure of integrity. I did that without really filling in a lot of the details of the hypothetical case. That was intentional. I don't think it's actually relevant whether the assignment is pointless (or whether you, from your definitionally less-expert position, think it's pointless). I work very hard to make good assignments and I know the majority of my colleagues do too, but that's not actually what's at issue.
The reason I can so plainly say that AI use is 'doing the wrong thing' is that the vast majority of the time, by using it you are violating the terms of an obligation that you made. The syllabus for the course is a kind of contract. The instructor promises to teach you everything on that syllabus, in the manner described on that syllabus. And you promise to a) take responsibility for what the syllabus asks of you and b) abide by the terms of the class. By taking that class, you bind yourself to the syllabus terms. This is why we always insist that you read the syllabus, by the way. It's really important that you know what you're agreeing to!
And on my syllabi, and those of most others, one of those terms is that your work must be your own.
Going back on an agreement because you don't feel like fulfilling it is prima facie bad. Lying about it is worse. It doesn't matter if you think your end of the bargain is stupid. By accepting the terms of the class, you have agreed to write your own damn essays and I expect you to do it and I especially expect you not to lie to me about it. If you don't accept the terms, you don't belong in my classroom.
Honouring your obligations is the most basic aspect of integrity. I don't want to live in a world in which politicians and the like think that giving their word means nothing and that they can go back on an agreement at any time. I already live in a world like that and it sucks.
(Aside: I think students don't realize how sad it is for us instructors when we get a whole inbox of AI assignments. Imagine spending hours every week talking about your favourite thing to people and then all of them turning around and saying 'yeah we don't give a shit'. I know a lot of people who are thinking of leaving academia for this reason - it's just too emotionally taxing to be lied to constantly about the thing we care about the most in the world. Eventually it's just not worth the shit pay)