Can't perform any research, compare conflicting sources, or self-reflection.
It was not just "turn in the paper at the end" but turn in your topic with a paragraph describing it. Then make an outline, then bibliography of the sources we were using. During the process we had to use 3x5 index cards with various points, arguments, facts, and the specific pages in the books listed in our bibliography. We did this because this was later used to make footnotes in our paper.
By structuring the project this way and having each milestone count as 5-10% of the overall grade it made it much harder to cheat and also taught us how to organize a research paper.
I suppose you could ask ChatGPT to do the entire paper and then work backwards picking out facts and making the outline etc.
There's a good question about the future and utility of long at-home research paper projects in school, but it's not a cornerstone of education.
In 9th grade I procrastinated the semestral paper so much that I bought an essay online that explored unexpected gay themes in Ray Bradbury's corpus of work. I was so lazy I didn't even read it first, only skimmed it, and then back to Runescape. So it's not like this is a new problem due to LLMs, and I think take-home semester projects are all quite bad for these reasons that predate LLMs.
(It turned out to be such a phenomenally audacious essay that my teacher started fascinated email correspondence with me about it and I was forced to not only study the essay but also read the quoted parts of his work. Ugh, backfire.)
One of the reasons I mentioned the viva was an example of how we can decouple production of some work from an assessment of quality and some reason to believe that some candidate is capable of the work without assistance.
It would be unreasonable to spend five or so years working under examination conditions. But that doesn’t mean we can’t subsequently examine a candidate to determine likely authorship amongst other things.
But, for example, high school AP English exam is 3 45 minute essays (plus multiple choice). You have the read the passages, compare/contrast, etc.
The problem is more with teachers lazily slapping an essay on a topic as a goto homework to eat even more of the already limited students' time with busywork.
I think it's probably more concerning that spitting out the most generic mathematically formulaic bullshit on a subject is likely to get a decent mark. In that case what are we actually testing for?