Surely the most effective design for governemnt systems
Is that they are not connected to the known compromised internet but instad have their own isolated network.
History has shown that anything on the internet is a target and the costs of not being connected has got to be cheaper for the Government than employing yet more snooping on local internet traffic.
Especially when the goverment can mandate networks carry their stuff for free via a nice tax for those that refuse.
This is, for the most part, taxpayer fund infrastructure both in terms of original build but also all the bungs to BT over the years