It does seem to me, reading online the past few years, like there has been an inflation in difficulty of a certain category of interview questions, as a result of people studying.

Usually, when interviewing people on an algorithms interview, I've asked an straightforward warm-up question, followed by a more interesting second question, that might be difficult for somebody that hasn't thought about anything interesting in 10 years. I don't think there was ever a situation where somebody got through the first just swimmingly, and then hit a wall on the second. The pain always starts on the warm-up question.