In the long run I'd go with crypto-assets (not necessarily BTC).

No sovereign currency is predicated on a fixed amount of gold, nor have they been for 40 years. It's really a vestige of another time.

But people have faith in it, which is why gold defies gravity. Same can be said by crypto-assets (I've stopped calling them "currencies" because they're just not.)

So which leap of faith are you going to take? The one that comes in 12.4kg bars, or the one you can link to ApplePay?