AI has drastically reduced the cost and concealment for cheating, even in offline exams. A single person can easily do that using glasses with a micro-camera & rice-sized earbuds, and almost impossible to be caught.
This equipment is not very common today, but if the smart glasses become popular, then universities (or proctoring centers) will get it.
And if they don't become common, then some fraction of cheating is acceptable, as long it's not too high. After all, one could do micro-camera + earbuds even before AI, with human conspirator.