You are overlooking what essential distinction between gold and bitcoin which makes them both irreplaceable. Gold is an actual/tangible material that was naturally produced and formed on Earth. Due to being highly-sought as a luxury and as an excellent store of value for investment, this precious metal has been skyrocketing its price over the years.
On the other hand, bitcoin has been around only for a couple of years but it has been one of the most controversial investment due to its high-volatility and decentralized in nature.

People always compare and contend that bitcoin is the digital gold of the era. Their similarities in price, usage, and supply are undisputed but what makes them distinct is their very nature. Gold will always have an intrinsic value due to being a precious material/metal but bitcoin solely exists on the internet.