>Pretending that an underlying asset that doesn't throw off any yield or return of capital is somehow more rationally valuable than another doesn't make sense.
Lets say I have a company with 1 billion dollar worth of assets and a 100 million dollar profit per year.
I have issued 100 million shares during IP. How much is a single share worth? At the very least $10.
Next year I have a 1.1 billion dollar company. How much is a single share worth? At the very least $11.
You have 1000 shares worth $11000.
I can now either pay the profit out as dividend or not. Your shares will be worth less by exactly the amount that was paid out. Your 1000 shares will be worth $10000 and you will have $1000 in cash or alternatively I don't pay out a dividend and you still have 1000 shares worth $11000.
Where did that growth come from? With a company it's easy to answer. They sold more of their existing products. Released a new product. Reduced costs through technology. We have more stuff now.
Investing in a stock helps a company indirectly even if stock buybacks never happen. The company receives better lending conditions from banks.
What about cryptocurrency? A currency shouldn't move in price at all. Where did that growth come from? From other people. Nothing new was created. Existing wealth merely gets redistributed.