I see this line of "I need to assess your thinking, not the AI's" thinking so often from people who claim they are interviewing, but they never recognize the elephant in the room for some reason.

If people can AI their way into the position you are advertising, then at least one of the following two things have to be true:

1) the job you are advertising can be _literally_ solved by AI

2) you are not tailoring your interview process properly to the actual job that the candidate will need to do, hence the handwave-y "oh well harder problems will come up later that the AI will not be able to do". Focus the interview on the actual job that the AI can't do, and your worries will disappear.

My impression is that the people who are crying about AI use in interviews are the same people who refuse to make an effort themselves. This is just the variation of the meme where you are asked to flip a red black tree on a whiteboard, but then you get the job, and your task is to center a button with CSS. Make an effort and focus your interview on the actual job, and if you are still worried people will AI their way into it, then what position are you even advertising? Either use the AI to solve the problem then, or admit that the AI can't solve this and stop worrying about people using it.