But to a large extent, what's wrong with that. Were Crystal Palace or St Pauls Cathedral essential infrastructure or were they vanity projects, built simply because they could be.
What's wrong with vanity projects? was every country that built a high speed railway wrong?
You've previously posted though, that the country has no money.
If we don't have money for essential or humanitarian spending, why should we find borrow some for vanities?
Also, as is the case with most UK capital "grand" projects, it is colossally overspent already, set to massively under-deliver; a vehicle to pour yet more public funds into chums' pockets.
The cost-benefit-analysis was, IIRC, fiddled, to make the project appear beneficial: something about business travellers stare out of the window for their usual journey (rather than work on their laptops), thus making the extra 15 minutes in the office a new gain, rather than just stealing that time from the slower journey.............
Finally, the environmental and social impact of Crystal Palace and St Pauls (your examples) is limited; HS2 has already seen thousands of homes compulsorily-purchased and razed, now for nothing, not to mention the woodlands and habitats that are now gone.
I attend regular meetings - with colleagues from all over the UK - in London already.
Why London?
Because it is already easy to get to, from anywhere.
All HS2 does is reinforces this - and further enables the concentration of wealth in the South-East - rather than making Liverpool to Leeds, or Newcastle to Manchester, easier and faster.
While "London" complains that it is overcrowded already, gridlocked..........so the "solution" is to grease even more people into there.......
The whole country gets saddled with more debt, for decades to come, to oil the path for London even more. With a few crumbs tossed to a very limited number of places, as a sop.