I only see $13T - the market cap of gold.
Everything else seems to be a different game.
Who holds fiat currency will not buy Bitcoin. For the same reason they did not buy gold or any other asset - they simply don't think beyond fiat.
Who holds stocks plays a different game too. They are investing in enterprises.
Same for real estate, bonds etc. Those are all different games for different types of people.
People don't need to think beyond fiat, they'll simply store their wealth where its nominal value goes up the most, especially if it offers the most liquidity, portablilty, divisibility, etc
Here's a good analysis: https://www.onceinaspecies.com/p/bitcoins-full-potential-val...