For BTC to absorb all stored value in the world, it would need to be the only currency in the world. That is the only way all assets in the world are bought/sold with BTC.
But that alone is, IMO, a non-starter. It assumes that all countries in the world would more or less give up control of their own currency and economy - if BTC is the only currency worth anything, why would anyone own or get paid in anything other than BTC? Which brings me to the next point...
This is not directed at you, but I think the BTC maxis severely underestimate the power and control that governments hold over these things. They can (and will) force you to pay your faxes, fees, and whatever they want in their currency, and have to power to use force if you chose not to.
If crypto poses a legitimate threat to that power and control, it is much easier to remove the threat than to adapt your system to it.