Also, the big car manufacturers have a huge head start in terms of actually producing a very large volume of cars across the globe.

If toyota decides they can make a yaris or aygo as a purely electric vehicle, tesla will be nearly unable to catch that large, low end market segment.

Also, you need low-end, mass volume cars to be able to push eletric infrastructure and replace the current gas infrastructure. (although i think using hydrogen and reusing the gas infrastructure might even be a better solution personally).