That regulation certainly didn't help. Though more fingers can be pointed around, I think, for what has contributed in important amounts. What also has to be explained is that the modern giant F-150 is just a massively popular vehicle vs. all other vehicles, even if I and other small truck enjoyers don't have much interest in one. I think the optionality of them helps them sell quite a bit. As one incentive, regulations on car seat requirements often come up in various government complaints, but the F-150s with a dual cab can fit 3 in the back (and under the seats and the truck bed handles whatever else like strollers and so on), so the vehicle can make sense as a family vehicle for a younger and not too poor family. Interest rates on loans being lower until recently also helped not so rich people stomach the financing, though sales have been getting back to 2019 levels so I'm not sure how much that matters. Any other aspirations like towing a trailer/camper, or taking it onto dirt roads, or doing occasional "truck stuff", make it all the more attractive even if the options aren't exercised or can be individually satisfied better by other choices.