If you want something gold-backed, just buy gold.
You could argue Gold is still a good alternative, but owning, transferring gold is problematic unless you actually store it yourself. Any "title" to gold somewhere else can inevitably be seized by a government (or your house raided). Encryption keys are much harder to seize if taken care of properly.
Venezuela, please. Bitcoin is never going to replace the ability of a sovereign state from issuing its own obligations. And as always it is the credibility of that sovereign state that will determine the value of those obligations.
And yes, I'm well aware of many such meaningless """cryptocurrencies""".
China is developing digital yuan so i am not sure what will happen to bitcoin that you own if the country deems it illegal.