Here is a short list of shit going on in Gotham at any given time, not including the wide array of psychopaths and supervillains doing shit at any given time:
- The insane asylum with the portal to hell (Depending on if you consider Living Hell canon or not.)
- The Lazarus pit in the city spewing chemicals into the water supply.
- All the other chemicals likely in the water supply from a wide array of sources, including regular pollution and goofy shit.
- The remnants of the evil warlock who was sealed under the city for centuries.
- The massive mafia presence and general corruption.
- The Illuminati that uses zombie soldiers.
That is not shit proper taxation is going to resolve. You can't protected bike lane away the zombie controlling Illuminati.