It gets a lot more complicated than that because setting up competing systems is cheap. It is like saying "nobody would write this piece of software for free". What we learned with open source is if the cost of distribution gets low enough then there needs to be just one person somewhere on earth willing to maintain it and it can work.

If the cost of creating trustworthy local (or international) monetary systems is basically 0 then it isn't obvious that plutocrats have an advantage beyond the one they already have by virtue of being powerful. If they can force you to use their system they already control the government so didn't need any technical help.