IIUC EWR is a private company so determines its own investment priorities and timescales (subject to market-related pressures).
Even if we had 'one railway' (eg BR, GBR?) there would be competitive calls on limited resources, eg finance, electrification teams.
There would be regions, sectors, whatever competing and each thrown a big enough bone (or cut) for some semblance of fairness.
There will never be total agreement on priorities; aspirations always exceed available resources.
I'm with Fishwomp on this- bird in the hand.
And with david1212 re false economy in 'the long run', but if money had not been wasted in starting too soon being so pleased to have funding open up so without proper site investigations ...
I would never have expected the dumping of the East-West Expressway, so good for EWR to make hay just now- they are trying. Hope there are no bats on the way. (Reminder bats in Wolvercote tunnel delayed Oxford- Marylebone by years)