I recently watched a video about why they don't sell small trucks in the USA. It indirectly addresses why Americans drive monster SUVs (and pickup trucks) instead of reasonably sized cars: CAFE.
https://youtu.be/azI3nqrHEXM?si=6k5j71W9zcuFbByECorporate Average Fuel Economy was created by the American EPA (Environmental Protection Agency, created by Dick Nixon of all people). The idea was that the average fuel economy of all cars a company sells must fall under a certain number. In the 1970s with the oil embargo, this actually led to companies literally giving away a subcompact when you bought a land yacht just to offset the average economy.
Anyway, the fuel efficiency on a per vehicle basis is determined by a large calculation, but the car companies discovered that the 'foot print' of the car was the biggest variable they could control. Basically, the longer and wider a car was, the more fuel it was allowed to use. So a giant pick up truck is more 'efficient' than a subcompact, and yeah, they convinced Americans no one wants to drive a small car because it was easier to sell big ones.
So yes, SUVs are a fad, but it's one of those government mandated ones created through unintended consequences.
As for the H series vs the E series, I don't really see the point. No one is showing up to watch the way the cars are powered. They want to watch a race. E might be better, H might be better, but they really do need more to differentiate the series.