The more that other fiat devalues, more people will use USDT
And the more profits Tether makes
The more bitcoin they'll buy as a result
And the more that Bitcoin grows in value, the more the proportion of value which Bitcoin backs USDT grows
And at some point, the value of Bitcoin that backs USDT > value of US Treasuries that backs USDT
And now you essentially have a currency that is backed by Bitcoin
What am I missing here?