Baskets or tied money have been around a long time.
the ECU is often forgotten.
All CBs will eventually issue their own cryptos, they're just playing a waiting game.
The volatility of BTC is only matched by the volatility of fiat currencies (those of us tied to GBP painfully know that - and the vol is definitely against us.
The only options, I see, in the future, is everyone actually creating / owning their own baskets, with XAU included.
XAU is heavily held by CBs for a good reason. They will continue to hoard it, and only sell when overstocked / market price is sky high eg Swiss CB several years ago.
John Reade, the strategist at the World Gold Council, is a good person to watch follow for XAU. He's worked at investment banks, HFs and now the World Gold Council, if you want someone to follow for Gold advice; I used to work with him and thoroughly recommend his unbiased opinions.
Also, it looks like what we have today is the opposite of the 1860s-70s. At that time it was a contraction of the money base, by abandoning silver and having all advanced economies move onto gold exclusively. That was because the then dominant empire and Bank of England had gold but not silver. It was the best way to preserve and even expand imperial power when Britain's real-economy output was beginning to be out-performed by Germany and the US.
(If you think Germany and the US listening to Britain and abandoning silver was foolish beyond belief, today's non-US central bankers are not much better --Napolean was probably right that bankers have no allegiance to their home countries.)
Today we have an expansion of the money base, or so I predict. Before Bitcoin appeared, the central banks had nothing by way of hard money. They had spent their gold and been playing with derivatives to stem the rise of gold, and their totally-fiat money had created the most financially unstable period outside the interwar, Great-Depression decades.
The CBs and establishment economists would of course talk gold down, but they know better than anyone that they need a monetary anchor, and quick. (Hence the stratospheric rise of Bitcoin.) Since they have nothing to start with, it benefits them to have as broad a hard monetary base as possible -- so it's not surprising that forked Bitcoins as well as altcoins are all surviving and rising.
The Great Convergence of 150 years ago is now the Great Divergence.
But they must walk a fine line. If Bitcoin's value is diluted too much by altcoins, the reputation and hence value of the entire crypto-as-money scheme is at risk. If Bitcoin is too dominant, the room for their future power is limited. So, we have something of a middle road: all major altcoins go up, but Bitcoin remains dominant.