I started leetcoding again this year because I want to jump ship and holy crap! I used to solve problems on leetcode 5 years ago (last time I switched jobs) and it was pretty laid back. Nowadays, I'm seeing dynamic programming with 3D memoization arrays like it's something normal. It all started like a way to check if someone knows how to write code or knows data structures and basic algorithms but now it's competitive programming level.
That's what happens whenever there is a competitive exam. Look at math olympiad papers from 1970's, and compare them to the recent olympiad math test. Tougher than 1970s. It is the same about many entrance exams we see in China, India, etc: older exams are easier than the recent ones.
People just master the foundations behind the old test material. Now that stuff has become trivia of the today. So, they need some advanced stuff to test the test takers.
