Apple has been in a long term iOS and iPadOS certification process with the German BSI (Federal Agency for Security in Information Technology). Their Indigo version of iOS has now been certified and Apple devices can be used in government agencies - they need to use certain MDM solutions (there are two currently certified).
Indigo (iOS Native Device In Government Operation) is a special additional security layer for standard iOS and iPadOS devices, providing extra security, so that they can be safely used by government agencies.
According to the BSI and the report, the tight integration of hardware and software gave Apple a strong boost in getting their products certified.
Link is in German.
https://www.golem.de/news/apple-indigo-ein-ios-fuer-die-deutschen-behoerden-2407-187458-2.html