Your example of electric cars doesn't really translate. In your example, people are buying electric cars because there is an intrinsic property to them that make them superior to alternatives (e.g. faster). With bitcoin, people are currently buying not because they believe something about bitcoin is better. Instead, they're following greater-fool theory investing.

Whether millenials have learned about existing financial systems or not is immaterial. It's unlikely they'd be holding a position in bitcoin if it weren't for the massive gains that have been seen in the past year. It's purely a get rich quick play for the majority of buyers today.