[cmurf]

Well, ostensibly, given enough time, we'd end up with a single code base, where the modular add-ons are really just about user interface, similar to how every county in the U.S. does their own ballot layout. In the old days, pen and paper could be considered to be a single code base. If you get the basic thing to do right, it's a choice, not a necessity, to have different code bases that do the same damn thing.

So eventually it would be less expensive than closed source, to implement and maintain. Basically wealthier and more ideologically committed states would subsidize that reference implementation, and the rest of the country, should they adopt that open source reference, would get to use the code more cheaply.

From a global perspective, there's a pretty decent chance a huge chunk of the code is already done - i.e. it could use the Linux kernel with a bunch of its more extraneous modules disabled. A handful of math libraries. A handful of UI libraries. And then a code signing mechanism from stem to stern. There's a lot more to it than that, but code wise, a bunch of it might already be written, the work is not innovating ducks but getting them in rows, and documenting it in a way that it's reproducible and ideally only boots up when it's exactly conforming to the spec.

Closed source with multiple competing companies nationally by definition means many different code bases all in different maintenance states. It really is wheel reinvention over and over again.