I voted against HS2 when Parliament was asked to make a decision on going ahead with the project.
I had read the business case, which was as thin as it was stretched. Returns were poor on a modest planned spend. How much worse they now look given the huge cost overrun.
The original case placed emphasis on shorter journey times by allowing the trains to travel at speeds which cars and coaches are banned from trying for green and safety reasons. When people objected that those on business could work on a train lowering the costs travel time, the government switched the defence of the project to needing more capacity.
It was never clear we needed extra north-south capacity.
The shortages were on prime commuter routes at peak hours. This ceased to be true after covid lockdowns led to much more home working.
It would be a good idea to pause additional contracts to build more.
The railways need to come up with a new business model now commuting is no longer so big. Railway capacity where needed can be increased with digital signalling.