It seems pretty obvious the puzzle algorithms are designed primarily with manipulating user subscriptions and engagement in mind, above all other factors.
Annoyed with the obviously unnatural rhythm of the puzzles (designed to trigger an addiction-aimed kind of irritation/pleasure cycle), I cancelled my membership. At the time, my puzzle rating was fluctuating long term between 2100-2500, but never higher than 2500. After cancelling my membership, the puzzles' texture totally changed to a completely different kind of annoying rhythm, and now the puzzles are uniformly unchallenging and unpleasurable, yet far easier to solve because they are almost all annoyingly easy.
My puzzle rating a couple of weeks later (after cancelling membership) is about hit 2800, after years of not breaking 2500. I have not suddenly, magically improved. The rhythm of the puzzles is just that manipulated, according to the site's goals for the user.
I doubt the site owners recognize how troubling and wrong this is.
Site owners: if you just produced a straightforward, non-manipulative algorithm, I would not have cancelled my membership. The way you have designed it, it is and feels hostile to any emotionally intelligent user. No neurologically normal person enjoys having algorithms try to hack their minds and actions, and more and more people are becoming literate about this being a techwide problem. You can be part of the solution, instead of just another creator of the problem. If you are experiencing a decrease in user engagement and subscription, you may need to wake up and understand that the way you are going about trying to manipulate users is the cause, not the solution.
So we all know about the annoying alteration that was made to the puzzles that makes the puzzle rating completely meaningless. But there's another issue with the puzzles that I'd like to address. My puzzle rush survival run came to an annoying end where I had a puzzle in which I played a winning move, however there was an even better move in the position. The difference was -2.6 vs -3.7. If there is more than one move that is clearly winning, the puzzle shouldn't exist at all! There needs to be one clear solution. It's so annoying to get a puzzle wrong even though the move you made is still winning. Please make the changes chess.com