Brazil's government-run payments system has become dominant

Given the fact that the central government uses taxes to fund the creation and managements of a countries currency, it makes perfect sense that in the digital age it should also be funding the infrastructure to send digital transactions with that currency. I wonder how differently the internet would have developed if microtransations were free and easy to transfer.

> Given the fact that the central government uses taxes to fund the creation and managements of a countries currency

That's not a fact, in fact it's typically the other way round, issuing a currency is generally profitable and the profits typically flow into the general government budget: https://en.wikipedia.org/wiki/Seigniorage It's managed by the central bank, though, btw, which is considered separate from the government for governance reasons.

Of course, none of that stands in the way of creating public payments infrastructure.

they do physically print the money (at some cost) . And they can easily generate revenue from a payments system, if they want to (which they will at some point, of course)

Creating digital currency can be as simple as incrementing a number or adding a ledger entry. Creating paper currency can be quite expensive. There are tens of billions of US notes in circulation.

Both are "profitable", as there is more money in the end, but governments are eating real costs to manage the physical bills.