In the long run, bitcoin is and will become a safe haven. Whether it is for any particular entry point in any particular geographic location for any particular holding period, that is a different question entirely. If you purchased in December 2017 from Europe or the US, then it didn't (yet) preserve your capital. If you purchase in December 2017 from Venezuela or someplace like that, then it did most definitely preserve a lot of your capital compared to holding your local currency.
Without a lot of additional information such as when one purchased, where one was when one purchased, and the timeframe that one intends to use it to protect one's value, the equation is somewhat meaningless. If you mined in 2010 and 2011, it has been a great safe haven.
Yeah, Bitcoin preserved a lot of value for Venezuelans, but still it lost a lot of value even for them if you invested in wrong time. This is why the best safe heaven for countries experiencing hyperinflation is the US dollar. With it you won't lose 30% of your wealth in a day. However, if you can't get your hands on it or other foreign currency, than Bitcoin becomes a good option. Also Bitcoin is easier to conceal, which can be a huge advantage in some situations, like escaping the country.