You're misinterpreting absence of evidence as evidence of absence which is a logical fallacy. clearly there's enough of a market for trustless wealth storage enough to support a $100 Billion dollar market cap. Maybe you think that the world will need less and less trustless wealth storage in the future and you're short bitcoin; it looks like the market is betting against you though.
2. If a significant number of people were using Bitcoin to replace currency usage, as per the original manifesto, they’d leave evidence behind. You’d see retail transactions, it’d show up in financial reports, the network having problems would make the news because of the inconvenience to businesses, PayPal and western union would be reporting lower usage, etc.
"Markets can remain irrational a lot longer than you and I can remain solvent."
https://support.microsoft.com/en-us/help/13942/microsoft-acc...