The economic reach of Bitcoin is an interesting subject of discussion. In the end there will be a maximum of 21.000.000 BTC. BTC is a eight-digit number.
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.
In fact, divisibility does not play the very first role. If states continue to levy a tax, then its easier for people to continue to accept euros / dollars than to accept bitcoins and then go through the circles of hell of a bureaucratic machine so that everything is acceptable. Retail is primarily sensitive to high commissions - and lower commissions than in the banking sector it will not work.And other areas are not so much interested in people. We get a situation when it will be profitable only on the periphery (Small cities in the countries of the second and third world, where there is no good infrastructure). Or, if there is a nonprofit organization that will provide at least all banking services at a price clearly lower than banking organizations (Although lending is unlikely to be cheaper, banks get money in Switzerland for less than 0%, for example).