I spent one day with Opus 4.7 to fix a bug. It just ran in circles despite having the problem "in front of its eyes" with all supporting data, thorough description of the system, test harness that reproduces the bug etc. While I still believe 4.7 is much "smarter" than GPT-5.4 I decided to give it ago. It was giving me dumb answers and going off the rails. After accusing it many times of being a fraud and doing it on purpose so that I spend more money, it fixed the bug in one shot.

Having a taste of unnerfed Opus 4.6 I think that they have a conflict of interest - if they let models give the right answer first time, person will spend less time with it, spend less money, but if they make model artificially dumber (progressive reasoning if you will), people get frustrated but will spend more money.

It is likely happening because economics doesn't work. Running comparable model at comparable speed for an individual is prohibitively expensive. Now scale that to millions of users - something gotta give.