Well if we're talking about that, then reciprocating engines can do pretty well (the prius engine is over 33% efficient when running in the ideal range, and it actually exists today; diesels do even better)
But maybe an electric car needs a gasoline engine as much as a tablet computer needs a keyboard, and maybe we're several years away from seeing that in the electric car case, just as the belief that a tablet didn't need a keyboard didn't become widespread until the iPad.
It obviously can still fail but I don't think it's possible to draw historical parallels.