A combination of incentives to customers, incentives to manufacturers, new lithium mines, more battery manufacturers, and improved manufacturing techniques is causing a dramatic drop in the cost of EVs, to the point that the average EV will shortly (i.e. this year) cost the same as a gasoline-powered vehicle. See this recent article from The New York Times.
The question is looking less and less about the viability of EVs and more about
- The capacity of the electrical grid
- The speed of the transition of the grid’s power sources to renewables, such as wind and solar
- Installing the required charging infrastructure, particularly for longer trips