Not quite true. As a student who had many friends in Serrano's class in question among others at Brown, I'm be quite doubtful that AI has led to an increase in this particular class. The truth is that (at least post-covid) cheating is very widespread on take-home exams. If you are taking an introductory class such as Serrano's, you will have many friends in the class and cheating is so widely accepted that there is little to no stigma to doing it and so many people do. The primary limiting factor on whether a student cheats is not access or ease but desire.
Hmm I think one part every commenter is missing is that students have grown way more mercenary and cynical over the last 20 years. I was shocked in grad school that:
a) I got bullied into sharing my math homework so people could copy it, just like high school and college... but this was math grad school!
b) In 2011 I TAed a 4000-level course where the instructor left the solutions to the homework online (he wrote the book). I estimate 95% of students copied the solutions. It was only 5% of the grade and they paid for it on the exams. Still. Kind of stunning to see at U Waterloo - it was a continuous optimization course and most of them wanted to work in finance, yikes.
I would not agree with this from my own experience. The truth is the culture, at least at Brown in the 2020s, has little stigma around cheating in big classes. Unclear how different this is in the past, but a friend and I often joke that the student body is very good at reward hacking. If there's a reward, people will find a way to get it! That's across grades (people will cheat), housing (a huge % people will competitively apply for specialty housing or accommodations to beat the lottery), and a whole lot of other things. I don't think this is correlated with legacy, athletics, ect. but an artifact of the current culture unfortunately.
I was in a class where around 12% of the class got caught directly copying a journal assignment. I'm sure more went undetected. AI has made it easier, but it's in the same magnitude.
It's a sad state of affairs.