Never. Bitcoin cannot replace Gold. We have to admit it. It may compete with Gold as a store of value and perhaps even become the preferred option for a short time but it will never replace Gold. Gold will always be gold. The preciousness of Gold is as old as civilization itself. And Bitcoin is not the one to make it worthless.
Bitcoin as a store of value can and will replace gold, not in the near future but 40 to 50 years from now we will definitely see bitcoin as a store of value that will replace gold. Bitcoin is a better investment if we compare it to gold, it is the new digital money that everyone should hold. Bitcoins is having a limited supply just like gold and is also easy to keep, you can even keep any amount of bitcoins in your pendrive too. The best part is, it gives more profit than investing in gold if you are an investment minded person.