How is it not useful for society if it’s worth $3300 an ounce? It’s a metal prized physical properties and it’s also used in industry.
So I'd say it's the same as having cash under your pillow.
I give my cash to you, and, as exchange, I will own a (usually small) share of your company.
Then you’ll hopefully be successful and my shares will raise.
Good for you. Good for me. Good for society since you created jobs.