Bitcoin has been confirmed as the best safe haven currency in the world with the following reasons.
1) If they is a military war, someone can easily move out of their respective country with Bitcoin. Cash, gold, silver is much harder to deal on.
2) The only one Currency not controlled by a government or bank.
I think that it is so popular because of this thing. It is not the same. It is possible to transfer quickly. It is not possible in the case of money or gold. Therefore its popularity is increasing more and more day by day.