We all know bitcoin's scarcity is far more guaranteed than golds, but this is the subjective part:
It's more precious than gold.
Obviously most people still value gold far more than bitcoin the marketcap difference itself is enough proof.
Well, I think any body who values gold more than bitcoin does so solely because gold is from ancient times, it's not man made like bitcoin, and it was once a currency and over time, have proven it's legitimacy and worth..
Bitcoin on the other hand is still pretty new to many people, alot of persons don't really understand bitcoin yet nor how it work, so they are still skeptical about the legitimacy of bitcoin, Infact, some still see bitcoin as a bubble, for such people, when you ask them to choose between bitcoin and gold, be rest assure they will always choose gold.