Never bothered the Victorians
There wasn’t the road network in Victorian times, so it was trains or nothing for rapid transit. Nowadays trains are competing with cars.
So we have made a high speed line between Leeds and London, where as the rest of the transport network is unreliable, falling to pieces, overpriced and overcrowded.
Gotta start somewhere! New lines would seem to be just what’s needed, for the exact reasons you state.
I dont think it will bring jobs and prosperity
Its surely just a plan to make London Commutable from anywhere in the UK.
If you live in Leeds and commute to London, you’ll bring money back to Leeds where you and/or your family will spend it at local businesses.
That’s ignoring the businesses that may locate there because of the access to London. That’s why so many businesses are in places like Reading, Camberly, Farnborough, Slough etc etc. Cos it’s handy for London but the property’s cheaper. Property will be even cheaper still in Leeds.