I was talking to someone who was excited that he was able to use ChatGPT to convert a short tabular text listing of about 70 rows to a comma-separated list of the ids on each row, without having to e.g. import it into a spreadsheet or database. I pointed out that this couldn't be relied on, but he was skeptical. So I checked the output he pasted - there were only 69 ids. It had left out an id from the middle of the list, seemingly at random.