> Eventually, the world changes and the company makes a few missteps, and then one day, bang!
That's not how bankruptcy works.
Kodak, Sears, K-Mart have proven that it (typically) takes years, maybe even decades, for a dying company to go bankrupt.
> The company is bankrupt and your share is worthless.
That's also not how bankruptcy works. Your factory equipment will be sold to the highest bidder, and your shareholders will be given the money that was left-over (after bondholders and suppliers are paid).
> Without dividends, the stock market is a zero-sum game.
Also a false assertion. The stock's price is most commonly tied to the equipment, land, and other resources a company holds.
If the equipment, land, and resources "suddenly" become worthless, then yes, the company is worthless. But in practice, land, equipment, and resources have real value. And that real value, is often above-and-beyond the cash value of those resources.
Tesla paid $5 Billion for the Gigafactory 1. I think it was a bad purchase, but the shareholders own the Gigafactory. I would never buy Tesla shares, because I think Tesla overpaid for their equipment, the land, and the workers at that site.
Tesla was ONLY able to buy the Gigafactory 1 because a pool of investors brought together $2+ Billion in 2014 (a secondary offering). The bond market handled the rest of the debts needed to build the factory.
As long as the Gigafactory 1 makes more than $5 billion over time, then Tesla will be a good buy for its shareholders and its managers.
(Unfortunately, Gigafactory 1 was a bad buy for Tesla and Panasonic. But that's another topic....). Most importantly, Tesla shareholders own a stake in that factory (and every other piece of Tesla). If it weren't for Wall Street organizing things, the Gigafactory 1 would never exist.
That's the power of the market: to conjure up $5 Billion out of nothing but the hopes-and-dreams of millions of investors, to hopefully make a factory that will hopefully make enough cars to be profitable.
And guess what? If Tesla goes bankrupt, those investors are happy that Tesla tried. So the market is very far away from a "Zero Sum" game. Go and ask any Tesla investor if you don't believe me. The vast majority are bought into this "changing the world" story, and are willing to lose money over it.