If you're doing this at least face to face over Zoom and you can't tell that someone is copying answers from their second monitor and throwing ChatGPT explanations at you, you honestly need a better interviewer.
I've done a lot of interviews over Zoom, and whenever someone cheats, by passing someone else's work off as their own (the weirdest thing I've ever encountered was someone having a friend on trying to feed them answers, which he admitted to later) it is so painfully obvious if you grill them a bit and throw a few curveballs.
If you believe your catch rate is 100%, just because you've managed to identify a couple of people who were really bad at it, you might want to check your priors.
I didn't say my catch rate is 100%. But catching the people who are bad at it is the entire point. I don't care about not catching someone proficient enough they can hold up even in a direct conversation where they have to explain what they did. That's someone who is likely just insecure but smart enough. They still shouldn't cheat, but they're at least clever. I had an old teacher who used to joke that you're allowed to cheat during the exam but you can only bring a small note card, point being that if you put enough effort into preparing your cheating that it fit on the card you were good enough to just take the actual test.
It's the people who have no idea what the hell they're doing and who try to pass of a solution they can't explain and by definition those people you will catch if you know how to interview.
I've done a lot of interviews over Zoom, and whenever someone cheats, by passing someone else's work off as their own (the weirdest thing I've ever encountered was someone having a friend on trying to feed them answers, which he admitted to later) it is so painfully obvious if you grill them a bit and throw a few curveballs.