[mjevans]

The parking spaces are still there because the city's 'density' or 'daytime population' was pumped by ecologically unsustainable commutes.

The US has never had a high level civic planning process or ability. Housing ends up built where-ever, and it's often cheapest to go built it in places with less regulation. Like wild frontiers in not even states. Or in areas outside of city limits as a tax dodge. There also aren't formal processes for renewing areas; instead informally they're allowed to decay and crime rise, and eventually reach a point where it becomes 'economically viable' for building something new.

Those lots exist because there's still enough whatever is desired in the city you live in, probably too much retail and office space. Probably not enough apartment / condo / housing space, but none of those investors want to admit their market was over-valued and de-value the present investments so they'll happily keep supply low and rents high.