Harari sees history as fiction. But I think we need to make a distinction between fiction and physical reality. Gold is a physical reality that got married into human's fiction.

DEC technologies are still around. They just got replicated and extended into other technology stacks. It's not easy to replicate gold. The easy way is to mine more gold. Technologies are ideas. Gold is physical.

Bronze and iron became less popular after BC. Will steel go away any time soon? No. Humans have worked with gold much longer. Gold has had its ups and downs. It has always come back for thousands of years. This suggests it's not going away (Lindy effect).