Please, they never even tried for the most part, they just wanted some easy bullshit tool where they could click a button and not worry about it. This bullshit predates AI by the way, companies like TurnItIn should be sued for fraud because people who actually wrote stuff have been falsely accused and people who plagiarized shit went undetected. These bullshit software packages never really did what they claimed to be able to do.
You want to actually stop AI cheating? Easy: In person tests and essays where the teacher is actually paying attention; no computers, phones, or other smart devices. Problem solved, you're welcome. Yes "professor" that means you have to do your fucking job instead of clicking buttons in Learn or Canvas or whatever dumpster fire on an LMS you're "teaching" on. Cry more I guess? People are paying a shitload of money for this, take it seriously, asshole.
Sorry, I've had some shitty professors.