I don't/won't cheat, as I am a rather anxious person who can't really handle "covert ops". But at this point I totally understand those who do.
I think LLM performance on previously seen questions like interview questions is too good for it to be allowed. I wouldn't mind someone using an IDE or API docs, but you have to draw the line somewhere. It's like how you can't use a calculator that can do algebra on a calculus test. It just doesn't accomplish the goal of testing anything if you use too much tech, and using the current LLMs that all suck in general but can nail these questions that have a million examples online is bad. I would much rather see someone consult online references for information than to see them use an LLM.
Top athletes do it because they're essentially at the limits of human performance and those drugs are the only edge they can reasonably get.
Different people have a different threshold for cheating no matter the stakes. I imagine some people vheat even if they know the answer - just to be sure.