Lies, dammned lies and government promises
When the government tries to give you something "for nothing" you had better check the small print (or count your fingers). Having chosen the most expensive and risky option the government needed to construct a reason for the public to buy into the idea, hence the risible savings idea. Everyone including the government and suppliers can see that this is nonsense but they don't know how to stop the programme having spent so much of the budget without achieving any meaningful result. Their mindset only allows them to plough on regardless - how many programmes have we seen in this position? It needs balls of steel (sorry Theresa, Rudd et al) to stop this nonsense and given the example of the Brexit show I doubt it could ever happen, short of war.