No, this is false. With stocks, the holder can get paid in dividends. With real estate, you gain value from actually using the land. A bond is actually a form of credit. Et cetera. Which other assets are you thinking of?
Edit: You must be conflating it with the funny money private stocks and their buybacks that a lot of startups have. Those are obviously a gamble, they're not really "investments" for most participants. It's no surprise that the same type of companies tried to go deep into ICOs a few years ago which are like the crypto equivalent of a bogus penny stock.
> There's a losing counterparty in every winning trade
the counterparties are equal in every trade; any winning takes place afterward in the future
and if one party is selling a publicly traded security or commodity at a loss, that doesn't mean it wasn't a good investment, it means it was bought at a fair price and conditions changed
That's true for practically every asset class. If you sold your Netflix stock at $600, someone had to buy it at $600 as well. And now they're out of $430.
There's a losing counterparty in every winning trade.