Before around 1960, domestic autos were one size, basically, full size, though you could get two doors, four doors, and wagons, and they started with 2-3 trim levels. Americans like choice. VW introduced the Beetle and it had some success, so GM countered with their rear engine car, which didn't do that well (Nader did a hatch it job on it, largely out of ignorance).
Then, as there was consumer demand for smaller cars, GM et al. started providing a Chevelle and a Chevy II, so you had three sizes to fit your needs. I think personally they went overboard, and of course ended up killed off Olds and Pontiac. I think they should have killed off Buick and kept Pontiac, but whatever.
Nobody but GM tried to build an EV in the '90s, and the GM-1 demonstrated that neither the demand nor the technology was available. Tesla worked on both items of course and has done an amazing job in my view. The standard automakers appear to be catching up some, but they still sell at a loss whatever they sell.
We will hit a point in X years where half the new car sales in the US are EVs (not trucks). My guess is 2030-2035. It hinges a lot on battery tech and cost.
