Sales for true "SUVs" (ie. cars that are built on top of a truck platform) have stayed relatively stable, and most of the "SUVs" you see are actually crossovers[1]. This might seem like a pointless distinction, but crossovers are closer to cars than SUVs, and aren't as bad for the environment as you think. The best selling crossover is the Toyota RAV4[2], which gets 30 mpg. The best selling sedan (Toyota Camry) gets 32 mpg, or 6.7% more.
[1] https://advocacy.consumerreports.org/research/the-rise-of-th...
[2] https://www.caranddriver.com/news/g43553191/bestselling-cars...