At least near me the biggest problems facing the "urban" district compared to suburban ones is declining student populations as long time homeowners age in place and the maintenance costs of 100 year old buildings compared to 10-20 year old ones in the suburbs. Teachers tend to get paid the same or less in the city district and administration counts are higher but fairly close on a per student basis compared to the burbs.

This is before you get into the socioeconomic factors that make one student population more susceptible to starting and falling behind.