If you realise what goes on within the authorities, then this will be of no surprise to you:
Do you recall the video clip from Mike Maloney, titled "The Biggest Scam In The History Of Mankind - Hidden Secrets of Money 4 | Mike Maloney" (hyperlink: https://www.youtube.com/watch?v=iFDe5kUUyT0) ?
Then you should be aware that, even though it is possible for the High Speed 2 to be done quicker and with lower price, the authorities refuse to speed up progress and reduce cost on the High Speed 2 project.