A root factor was the CAFE standards excluded trucks so manufacturers built SUV's on truck chassis to comply, and then could put more pollution in them at lower cost, plus again, bigger profit margin.
If there wasn’t sufficient demand then profit margins mean little. Ultimately the driving factor is that SUVs and crossovers are what (American) consumers want. So that’s what is being built.
There are a dozen or more cars out there, crossovers and SUVs are what marketing tells them to make. That and dodging fuel efficiency requirements. Take a look at Fords entire lineup, EV and gas. The only car is the Mustang.