The difference is huge. Put yourself in the shoes of a student.
The student you're copying from won't be sitting next to you for the rest of your career. The LLM probably will be, and you'll be probably expected to use it, so why not use it here as well?
All your peers are doing it too, and look at all the cool things they're doing while you're struggling with the basics. And what if the LLMs keep improving at a high rate? What if being able to use them efficiently turns out to be a more important skill than what you're being taught anyways?
This is why assessment needs to return to taking proctored exams, and away from coursework.
Well, if they don't know how to do the work, they fail the exams
> why not use it here as well?
Because you're paying a lot of money and opportunity cost to learn how to do something. No one needs the assignment. It's there for you to learn. You were given the assignment for you. Any adult should be able to understand this. We're not talking about 7 year olds asking why they need to learn to multiply when a calculator can do it better than them. These are 20 year olds. If they don't have the maturity for this, a university should not be accepting them.
Being able to use LLMs efficiently isn't a specific skill. It's a reflection of your ability to articulate what you want, which is a reflection of your understanding of the world, which is what you're in school to build. Terence Tao can get an LLM to do math better than I can. I can probably get one to build software better than he can.
And you can still use one to do cool things like your peers. Just not your assignments, the purpose of which is literally to teach you the basics that you're struggling with and that you're there to learn in the first place.
This is like why don't you copy out of the back of the book or look up proofs on the internet. It's all there, but doing that completely misses the point of why you're there.