Trillions? 50x the size of Ford? Bigger than, essentially, the current combined value of every car company in the world at the moment?
How?
Back in the 90s I bought a Rio PMP300. Before anyone knew what MP3s were, it was the first mp3 player out there. That didn't help them when people did care about mp3 players - bigger players just came and ate the cake. I'm not sure what makes Tesla a different story. Seems like it was supposed to be "Autopilot", but we all know how good that's going.
As to why Tesla could be the winner? One reason is that all the other automakers are failing to produce mass market EVs that anyone wants to buy.
We consider every vehicle brand a joke aside from Tesla.
Tesla's quality has dropped so much that JD Power's latest survey ranked it near the bottom in terms of quality. Everyone that has a Tesla says that they are fun to drive (they are) but they feel cheaply made.
The European car manufacturers are coming out with electric cars and I think they're ability to create a luxurious feel will make a big dent to Tesla's sales. Case in point, the Porsche Taycan looks amazing and will be a competitor to the Model S.
Every known vehicle manufacture outside of trucks & SUVs have no brand value to "millennials". I don't know anyone I communicate with who is excited to buy a ford, toyota, and or even a porsche car.
So you could make a reasonable argument that the huge stock price appreciation in the last 12 months was in fact a re-pricing to reflect that the stock market now believes Tesla has a decent shot at becoming one of the world's leading tech companies.
It doesn't reflect that something magical has happened in the last two years; something good has happened in the last 6 years and the stock market at large has only recently realized this.