What is useless is fiat money, at least as a store of value. The idea was great, let's make paper gold (dollars) so we don't have to bother moving the yellow rock around. Unfortunately, they broke the peg (surprise, Not!) and fiat became an infinite abundant worthless currency, like sand.

The use of gold in engineering or even in jewellery is insignificant compared to its real use as a store of value.

Gold is good, Bitcoin is better (as reflected in the price) and fiat is zero. Scarcity is the key point here