Tesla is not as far ahead as you think, in my opinion.
Tesla is a poor car manufacturer with an old Toyota facility and a limited market, for a car relying a lot on expiring subsidies. They struggle to make cars with consistent quality and fit and finish.
The company is burning cash and loses more as they produce more cars. I realize they have made a small profit the last 2 quarters, but they have vaporized billions overall and still lost over $1B in 2018.
Once competition cares enough about EVs to make them, you’ll see the lead evaporate quickly because there are highly competent competitors with much stronger brands and far better production ability. Watch a BMW being assembled.
BMW shipped over 100,000 cars with some electric component and something like 50,000 all electric vehicles. You think they are just going to die when the electric car gets big? And BMW is a stronger brand.
Electric vehicles are still a ways off and have many drawbacks to gas powered cars as of today, mainly cost, range, electric stations, needs for special home equipment, and ease of fill up.