This is my experience as well. I used \fast in the past when
https://x.com/thsottiaux announced a reset but didn't see a huge difference except draining the allowed usage faster. The target audience for \fast seem to be impatient people, especially those who want to one-shot things like a website or a 3D game. I also have a feeling that newer models optimize more and more for that audience because they are very active and loud an YouTube & Co and generate a lot of hype marketing.