From my perspective, the main advantage of a SUV is the higher vantage point to read traffic from (which is a big advantage).
The advantage (for me) or a sedan (or coupe) is better handling and better gas mileage (better aerodynamics).
Interestingly, the gas mileage advantage of a sedan seems to be dropping. Witness the Chevy Equinox (SUV) at 26 city/32 Hwy. (compared to the Chevy Cruze at 28 City/38 Hwy); I'm not sure how they are doing it, but that is not near so large a difference as was 10 years ago.
Also the cost benefit of MPG is not linear. In other words, going from 10 to 20MPG saves much more than going from 20 to 30MPG.
For example, given:
15,000 miles driven per year
MPG = 10 yields 1500 gallons of gas required
MPG = 20 yields 750 gallons of gas required (750 gallons savings as compared to 10 MPG)
MPG - 30 yields 500 gallons of gas required (250 gallons savings as compared to 20 MPG)
MPG = 40 yields 375 gallons of gas required (125 gallons savings as compared to 30 MPG)
So maybe the economic advantage of a sedan is being lessened?
An aside: With all-electric SUV/crossovers like the Hyundai Kona having a 300 mile range priced less than the Tesla 3, I can see the model 3 dying. I hope Tesla has a SUV on its way!