I'm looking for that link to the Digital Public Infrastructure blog post. But I also want to challenge the idea that government should be building or maintaining open source code. Maybe. But good open source code is maintained by a robust community of users/developers/designers.
There are now lots of open source projects started by government agencies. Some, like UK's Notify, have proven to be quite useful to others and there is a growing international community around it. This isn't the norm though.
I would much rather see governments focus on nurturing the ecosystems and learning from communities outside of government who have been working in the open for decades.
There have been calls by others for government to specifically support issues that align with their mandate. Accessibility is a clear one, but so is security and sustainability. Here's a post from someone in the Drupal community that is developing a tool very useful to government agencies (the webform module that allows for accessible surveys) - https://www.jrockowitz.com/blog/government-accessibility
Government needs to think about free software not in terms of free speech, but rather free kittens. You've got to feed/care for them if you want them to grow up into well trained house cats.