Stocks in principle are used to represent ownership of a company. Companies sell things, and should provide returns, if nothing else as their assets grow due to profits.

Real estate, while it does not grow exactly, is needed for almost everything else. People need places to live, places to grow food and other crips, places to build schools and factories and restaurants and so on.

You're right that gold is the same as crypto currency though. It's valuable because we have all decided that it is valuable.

I have no idea what you mean by credit cards. That is not an investment. 😅