"Tesla Motors was incorporated on July 1, 2003, by Martin Eberhard and Marc Tarpenning. Eberhard and Tarpenning served as CEO and CFO, respectively." "Tesla's first car, the Roadster, was officially revealed to the public on July 19, 2006."
"The Prius was developed by Toyota to be the "car for the 21st century; it was the first mass-produced hybrid vehicle, first going on sale in Japan in 1997 at all four Toyota Japan dealership chains, and subsequently introduced worldwide in 2000."
I will concede that Musk may have made some marketing decisions that contributed to the popularity of Tesla cars vs other brands but I do not believe that "Without Elon we wouldn’t have a viable electric car industry." If there is money to be made in a business then someone will inevitably step in to fill the market niche. That's a core tenant of how capitalism is supposed to promote the efficient use of resources.
Also, I'm not sure who the "we" in your comment is referring to. I personally do not have any type of car industry, viable or not. Are you suggesting that US car manufactures should be nationalized and owned collectively by all citizens?
Furthermore, I do not support electric cars as a major contribution to the solution to climate change.