What I've noticed is that "new style" government projects like the GDS seem to be suffering from using too many "innovation tokens" [2], probably due to the much cited lack of leadership.
It's not nice to be in a situation where you are stuck on a legacy Java 7 platform, and nothing else, but equally, it's not nice to be in a situation where you are trying to support and context-switch between too many stacks. One is too conservative, the other is chaos.
If there's no leadership, there's no-one to make decisions to limit proliferation of new technology. This might be unpopular for some developers looking to improve their CVs, but necessary for the organisation as a whole.
[1] https://www.bbc.co.uk/news/uk-politics-28464002 [2] https://mcfunley.com/choose-boring-technology