There are two sides to every transaction.

In this case 1/2 of the trade is a dead end. In another hypothetical transaction we might see that the money was instead used to pay for services, and that profit was then spent on food, and then it was spent on fertilizer, and then it was spent on chemicals, and then it was spent on mining, and then it was spent on energy, and then it was invested in.... You get the idea. You can follow a single dollar around the world for years. The money is exchanged, and then exchanged again and again generating profits and adding value to the economy with every exchange.

With the purchase of gold that half of the transaction is instead just... dead. The money is no longer in the economy, it's locked in some dudes junk drawer or a safe instead. Worse, it's not being used to generate excess returns like all of the items above are.

Gold is just... useless. Except of course as a store of value, but even then it's only good if you think the dollars value will decrease and don't care that it's not great for the world around you to extract money from the economy and render it effectively dead.