In the early days of the EV, one of the biggest concerns was range anxiety. EVs were slow to charge and had considerably lower range than they have now. There were no rapid-charging stations yet, hence making EVs non-viable in areas without the infrastructure (e.g., rural areas where charging stations may be far in between).
Perhaps for alternative technologies to prosper, there needs to be adequate infrastructure, supply chain, and reliability in the first place. Perhaps that's the main contribution of Tesla. It made electric vehicles cool, thus accelerating demand for both vehicles and the infrastructure to support it.