[FirmwareBurner]

>or lower demand (improve transport into the city, make other parts of the country more attractive to live in)

That's a chicken and egg problem. Most companies want to hire where the labor already is, aka the big expensive cities, and most workers, especially immigrants from abroad, want to live in the big cities as those have the most jobs and the population there is less conservative and racist towards outsiders meaning it's also easier to build relationships and get along with just English without having to struggle with the local language.

It's nearly impossible to convince companies and people to invest in small cities on the offshot that they naturally become the successes they dream of later since it's not something the government can guarantee, nor do we live in prosperous times of cheap money pouring from the sky that would enable governments to fund crazy projects of building attractive infrastrucutre.