You raise an interesting point about the scarcity driving appreciation for both gold and Bitcoin. It is true that a finite supply like Bitcoin's 21 million units establishes a unique and predictable scarcity that history has not previously realised in a digital form.
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If you look at the Sharpe ratios for both, at least since 2018, they tend to cycle against one another. When BTC's up, gold is down, and vice versa. They are an asset class unto themselves, and where capital flows seems to have something to do with relative (perceived) risk-adjusted returns.
That's an opportunity for a shrewd observer, and since they're both sound, it's an opportunity with less overall risk than many others.