The advantage of HS2 is not the reduction in journey times, it’s the increase in capacity. It frees up the other lines to be used more for freight and local services.
We clearly need to massively increase rail capacity and sort out the system.
It needs to run centrally to and from big cities. London, Birmingham, Leeds, and Manchester.
The Elizabeth line is a triumph.
I also agree that east west connections up and down the land need massive investment. Leeds to Manchester was a fucking embarrassment 10 years ago, let alone now. Oxford to Cambridge would be good. And we also need light rail / metro systems in many more towns and cities.
These were all problems kicked down the road 20 or 30 years ago.