Maybe you're right and in several decades BTC may become so appreciated all over the world that people will consider it national treasure. But now I don't see such tendencies.
bitcoin is not something created from the sky like other natural resources, bitcoin has a creator and even the fluctuations that I see are capable of being manipulated periodically, bitcoin is more feasible than generic stock market assets, there are many problems if there is a state of bitcoin claims as national assets.