I have this same suspicion. I dusted off a hobby Rails app from two years ago I was making with Cursor. I decided to try completely changing the main functionality of the app with the much better LLMs of today and was shocked how well it did with one-shot.

Now compare that to my recent experience with having Cursor help me work on a preexisting Node/React app...geez. What a pain. (It doesn't help that I wasn't the one that originally created the React app though.)