The key reason the annexation is costly boils down to too many roads. The maintenance of that infrastructure doesn’t pencil out compared to tax revenues in any low density areas anywhere.

The country currently takes that loss, but annexing it in just moves the burden to the city. The only parts of a city that are revenue positive are higher density areas of commerical districts, apartments, and row houses. Everything else is a money sink.

The roads and car infrastructure cost more then they bring in. The city is right to actually run the numbers before ruining their finances by taking in a massive area that leads to generational financial debt.