What I don’t understand is why governments don’t try to fund open source software.

Cyber is increasingly becoming an attack vector on key infrastructure and it would be so helpful to have a group of developers to be at government disposal while understanding what software is being run on.

I understand that China and a few other countries use Linux but this is not enough. https://en.wikipedia.org/wiki/List_of_Linux_adopters

Honestly any nation not named the United States should move to FOSS if they care about security. Imagine the keys to all important infrastructure being held by foreign companies.