Toyota forced a change in the car industry, and buyers' willingness to consider electric options, with the Prius in 1997.
Tesla was founded in 2003 to design hybrids. By 2008 the company had been taken-over by Mr Musk and changed focus to all-electic drivetrains and released the Roadster.
Nissan launched the Leaf in 2010 as the first mass-produced all-electric car.
EVs were coming regardless of Tesla. I'm sure they have helped promote the option and accelerated adoption within their target demographic but to 90%+ of the market they're irrelevant.
I think if not for tesla, other car companies would not be scrambling to make better Evs.