I suppose that a currency can only be leading if it has the possibility ta pay in small amounts, equivalent tot e.g. dollarcent or eurocent. This statement limits the range of BTC, will the satoshi be the future euro/dollarcent?
In that case the maximum money supply wil be BTC 21.000.000,00000000 is e.g. EUR 99.999.999.999.999,99 (by the way: interesting exchange rate).
The money supply in the Eurozone (M3) is over EUR 10.000.000.000.000
So without any constraints, the structure of the BTC satisfies the necessary condition.
Let's inventory the other constraints.