The network effect is a double edged sword that causes this extortion/coercion in a system that isn't permissionless.  In Bitcoin, you can go straight to the system itself and pluck the money off the tree.  It never ends, you can always do this.  It has removed friction from the economic system by removing the ability of the middle men to insert themselves and extort you.  The fact that it has permanent coin turnover means Bitcoin is essentially always running a decentralized exchange in the background to allow you to always bypass humans and you will always be paying fair market price.  In permissioned systems, that's not the case.  Most people don't even realize Bitcoin has it's own decentralized exchange, but it does.

Since, like I said, money is a unitary instrument, an engineering problem to create a decentralized price peg so that you can say 1 hat = 1/10th a chicken, the entire purpose of money's existence is to become a monopoly.  If the money is built by design as a permissioned ledger, it's usefulness to any person or nation on earth will be minimal and negative if it was to become a monopoly because it's too wide open to abuse.  It will either not be adopted at all, or scammers will try to force it onto people to extort them.  A permissionless system would have mutual value for all parties involved.

As for the company stock example, there are few companies that make things all humans are required to have.  When they arise, they're usually referred to as "monopolies" and broken up by laws, pitchforks, whatever.  The company isn't exactly the same category as "permissionless currency".  The main reason a country would want to resist a real permissionless currency, is so they can do things like devalue it to raise their exports, thus cheating other nations via currency wars.  There is a Nash equilibrium in every country adopting the permissionless currency to prevent each other from doing this.