Gold is no longer a means of payment and saying that something is good because it existed for years doesn't change anything. People were riding on horse backs for over a thousand years and then came cars bicycles and motorbikes.
I also don't believe bitcoin will replace gold but it will take a part of the market from it. If you give a young person a choice between 100 dollars in gold or 100 dollars in bitcoin most of them will choose bitcoin because gold doesn't grow in value as fast and people are gamblers in nature.