The economy isn't the same as it was 50 years ago. I don't think looking at history is a correct assumption any more. 401k's were mentioned above.
But there's a lot more to it than that.
People are more involved with their money than ever before. It's digital, not cash in hand. There's no physical things (bonds, stocks, etc) to hold any more. Prices are instant.
The fed is more volatile and reactive rate-wise and circuit-breakers to to stop things like 2000 and 2018 from happening ever again. It's virtually impossible to have a crash of 29 ever again.
Interest rates are low. Even at 'high' rates we have been seeing the past few years are still low compared to several historic times in the past 50 years.
And with that, the value of the dollar/CPI is ever-growing, so the trend up even at a light slope is normal just to break even in purchasing power.
The thing with Tesla is that the cars are just a derivative outcome of the real company - a technology company. Thinking of tesla as a car company is not correct (IMO). The tech and IP they hold is the real value.
We'll see this tech transpire into other use cases. No, not just driverless semi-trucks and all the other hype we keep hearing about, but into other real-world use cases like removing human error from things that are error-prone.
Surgery.
Air traffic scheduling.
1000s of other use cases could come to mind to augment the human condition. Just like a traffic scan, it can 'see things coming' before the human can.
Energy storage/battery tech and charging networks that are being established, along side starlink and other wireless tech, it's going to disrupt every traditional company today like comcast, frontier, cox, etc. cable channels are already dead with the apps replacing it. They are dead in the water if starlink can scale and meet the bandwidth and price point. Why would i pay to have lines run to my house when i can just get it over the air?
who has a cat5 cable from their router to their phone or laptop? no one any more. 20 years ago? at least 50%?
In the next 20 years, we're going to see a lot of disruption where connectivity as we know it (physical wires, plugs) is going to be obsolete.
On-the-road charging (think, huge Q chargers like your phone takes in the console of your car)
New government mandates for 'energy star' houses / new construction going to solar roof shingles (bye bye traditional asphalt shingles) aren't out of the question.
Retrofit companies will make a killing. And like most advancements, the 'skilled' worker needs to change. Not only do they need to lay shingles, they need to be DC experts running cabling and wiring up ATSwitches to the main box and all that.
This is why Tesla is valuable. They have pioneered a lot of this tech. And they have the buying power to swoop up startups with better ideas (like google and facebook and all the rest have done to stay relevant). And they have the scale to distribute it en masse quickly and profitably.
The 3/S/X/Y/Roadster/truck, is merely the first generation consumer container for some of the Tesla tech.