People (and government) will use the path of least resistance. Crypto is pretty liquid in many parts of the world now. You can P2P from crypto to your bank account and $10K is pretty feasible. However, $1Bn is not (outside the US and maybe EU). Once the liquidity is high enough, point 2 becomes possible. Point 1 always was.
Maybe BRICS will propose a solution that uses Blockchain to verify gold ledgers.
Historically, the dollar was the ledger and redeemable in gold. Which the USA printed a lot more than it said it did. A ledger would stop this kind of abuse.
If you're dealing with physical goods, there's always an analogue hole unless there's a (usually centralised) authority standing by to penalise attempts to subvert the system.
One can conceive of "for-now-unforgeable" NFT-isation of physical items, perhaps based on random physical phenomena like metal grain patterns, with the fingerprints stored in the blockchain. But this would be expensive and is a disadvantage compared to the "gold in a pile at least as big as we told you" system. And it's still open to kinds of abuse: e.g. you can secretly melt some coins down and recast them into new ones, as long as you can avoid anyone asking to see the "burned" ones, and you can also file fake fingerprints for coins that don't exist, that no one really owns, in the ledger so they won't need to be proven, but they inflate your ledger's value.
The problem with the gold standard era was countries, particularly the USA, claiming it had a lot more gold than it did and you just had to take them at their word. It wasn't until Charles de Gaulle called them out and demanded the physical transfer.
What you really want are audits.