In cases like cash or currencies, you may have the asset and can freely use it, but it does not have value due to a systemic issue. There may be too many units of the currency such that using them would not purchase very much (hyperinflation). There is also devaluation - where a currency is arbitrarily devalued due to some economic or institution issue. Most of these issues come from too much debt and not enough assets to pay for them. A currency devaluation is like a partial or slow motion bankruptcy for a government or issuer. In a foreclosure scenario, the creditors (or users of the currency) would be getting a fraction of what the asset (or currency) was originally worth.
One key aspect for both bitcoin and gold is that in creating either of them, there is no liability involved. National currencies are issued with interest attached, which means there is a liability to the issuer of the currency. The currencies due to being centralized can also be "delisted" or have their value altered, devalued or swapped for other currencies. With Bitcoin, there would have to be consensus among the players for this to happen. Gold is nature's money, and since it was found, there is no one really in charge of how it works. Gold also has the history of being used as money for thousands of years in virtually every culture and society. Bitcoin does not have this reputation. The internet, technology and power grid are needed for Bitcoin to function, whereas gold just is. The value of gold is based on what it is being exchanged for. The value of Bitcoin is similar to buying a stock or a good: It is determined by what the buyer and seller agree it is worth.
Are there regulatory, institutional or systemic risks with Bitcoin? The answer is yes. What if a bunch of central banks or governments took over the Bitcoin issuance? Would this not lead to control issues that could either stop the Bitcoin transactions or impair them? What if the justification was to stop terrorism or illegal activities? There are also technology issues like who controls the internet, the electrical energy involved in mining Bitcoins, or other issues in infrastructure (the electrical grid, the nuclear grid, the internet servers, the telecom companies etc.) Regulatory risks can also run the gamut from restricting who buys Bitcoins, how many can trade each day or perhaps issuing trillions of units of fiat currency and buying and selling Bitcoins with them which would cause convulsions in the prices of the unit, leading to mistrust and lack of use? Gold does not have these shortcomings. Once it is mined, it cannot get destroyed. It is not reliant on technology, infrastructure or any institution to make it valid. Since it is small and portable, it can be taken anywhere and still be useful without any other mechanism needed. The prevailing institutions can be changed many times and gold will still be valuable.
Gold is a classic safe haven because it does not need institutions to exist, is very hard to forge, cannot be destroyed by the elements and does not have issues of access or restrictions. Physical theft and restriction may be factors, but gold fares better than currencies or digital currencies at this point in time.