The price per kWh was dropping faster BEFORE mass market cars than after. It is not that we lacked the technology to build cheap batteries. It is that we lack the technology to scale them.

Tesla is ahead of the curve. Their aggressive efforts on supply chains and factories have reduced the cost of batteries for them relative to everyone else. But the end result is not a change in which technology will win. Instead it is a question of getting there a single digit number of years earlier.