Have you considered that Tesla might be the world's most valuable car manufacturer not in spite of not advertising, but because they are not advertising? If you go back to when you got your first Tesla vehicle, how would advertising have impacted your decision to get one?
EVs are a bit unusual advertising-wise since it's too easy for the average customer to independently figure out that it's nice to skip gas stations, noise and fumes in favor of a quieter and more powerful ride. Said consumer will then notice that there are too few EVs available and that they can't afford them.
Why does EV demand outstrip supply? For those of you who have read "Innovators Dilemma", this is obvious. ICE industry around the globe, ripe for disruption has been holding back the floodgates for 20 years. As the Li-Ion battery slowly scaled up in the 1980s, any businessperson or engineer willing to use a pocket calculator could in 5 minutes figure out the inevitable. By the late 1990s when Li-Ion batteries became a commercial success for computers and phones, it became obvious to most people that BEV was the way to go. Many of us where dumbfounded and disappointed by the that the big auto OEMs were not pursing it. There has been a huge pent up demand ever since and no advertising would have changed that. When Tesla as the first company presented compelling li-ion powered cars, people were poring over them. I remember wanting the Roadster really bad but couldn't afford an extra non family car. When the S came in 2012 it became a no brainer even for me to get one. If Tesla would have had to pay for advertising on top of it fewer had been able to afford the car. When the 3 became available for order, 100s of thousands of people queued night and day to order one. No advertising could improve the amount of 3s delivered.
The main issue was the production cost for a new manufacturer was high, making margins razor thin. Advertising could theoretically have increased demand and thereby price, and maybe margin, but I don't think so. In fact, advertising and a resulting higher price might have hampered Tesla's success since to the overwhelming demand was already present.
If you agreed with non advertising in 2012, you'd wonder at what point in time it would have changed?
IMHO, EVs don't fit the often cited Apple pattern of advertising -> demand. Apple created new products with new markets and new demand. EVs can't do that yet because there is no physical scaling capacity on Earth to satisfy new markets in addition to displacing ICE production, of which there is 850% EV growth remaining until ICE production is displaced.
The fundamental problem with EVs, not only Tesla, but the whole industry, is demand is, for now, insatiable while production cost is high because of inferior scale. Advertising would lead to fewer sales due to higher cost.
The only EV advertising that makes any sense is advertising of future superior or imaginary EVs of ones own brand to steer one's buyers away from present day EVs in case one doesn't have production capacity to fill that demand. This is precisely what the ICE producers are doing.
If Tesla wanted to spend money to generate demand now, there are a lot of low hanging fruits that are probably more in line with the mission. Improved customer service, more superchargers, more destination chargers with Tesla signage are some examples.
In the future once ICE production is mostly displaced and EVs have become a commodity themselves, advertising might pay off.