As of now, Tesla is having a virtual monopoly in the mid-range and high-range EV sector and that explains the high valuation. There is no doubt that a P/E of more than 1,000 looks hyperinflated. Even during the dot com boom during the late 90s, most of the tech stocks had a P/E ratio of lower than this. But those who invest in Tesla believe that EV sector will replace gasoline-run vehicles in the near future. As per their expectations, Tesla revenues are going to jump by 10x-20x during the next 10 years (if I am not wrong, then they had ~80% growth in 2020).
However people think that in the future it's going to worth even more than this, as long as electric vehicle line keeps going strong like this and they keep being sold out constantly that means the price of the stock will keep going up, and that is proven on the finances as well, it always grows bigger and bigger, so yes in the future it will be a lot higher but today it is overvalued so it's a very trick situation.