the initial goals of the project (to connect Northern England to London).

This was never the goal. Northern England is already connected to London. But the trains to London use the same trains as local commuter trains, which don't work as a reliable commuter service because they have to squeeze into the gaps between fast trains, and get held up every time a fast train is running late.

HS2 is about giving the fast trains their own track so that local trains can function properly.