The US government of yesteryear recognized a problem, so they drew up legislation intended to improve fuel efficiency, and thus reduce emissions. But they recognized that certain trades required large vehicles that could never be that efficient. So they built in a loophole for vehicles over a certain size not counting towards the requirements being placed manufacturers. Manufacturers being the crafty hogs they are realized if they just increased the size of everything they wouldn’t have to follow any of the rules. Now you have a company like Ford that only has one actual car ( a muscle car at that) in its lineup. Everything else are trucks suvs and crossovers.

The government of today could rewrite these rules to make the loophole require business licenses or something else, but half of them refuse to see there’s a problem at all, and half of what’s left are in the pocket of the problem makers.