True. But that is irrelevant to the original point: Cryptos are as much investments as any stock or commodity. And anyway, that future expectation of profit ought to go into risk-free treasuries unless you want to gamble on a specific, higher risk asset.

Wouldn't this expectation be built into the current price of the stock?

Yes, but money in the future is valued at a discount today. So even if an asset is 100% sure to be worth $100 a year from today, the market will value it at slightly less than that because there's no sense tying up $100 in capital for a year unless you get some profit in return.

the risk you take for those returns means the price won't fully match the expectation. but you can mitigate that risk via diversification.