From what I've seen, it's because the last 20 years (at least -- I wasn't politically conscious before then) of policy have only focused on London. The rest of the country has mostly been left to fend for itself, but have the additional burden of dealing with nation-wide policies that really only apply to single metropolis. And because Parliament over-allocates funds to London, that leaves most other municipalities to fight over funding scraps left on the table.

isn't London still paying more taxes than what's spent there?

though of course it's not surprising, productivity is vastly higher in cities. but that's an argument for allowing and helping them to grow more.

urbanization started many hundreds of years ago, it's nothing new.

in fact, instead of committing to economically (and ecologically) sustainable high-density cities (and withdrawing from the crazy American Dream/Nightmare suburbs)

letting people piss away their lives in shitty none of the above places