Imagine dividing your solar capacity among several hundred dwelling units in an NYC apartment complex and then you might be close to an apples-to-apples comparison to what this regulation means.
Cities will always require the import of significant materials, food, and energy from surrounding areas, and electricity is actually a more efficient means of importing energy than natural gas is. Replacing all the diesel trucks and buses with electrical versions, that's equally desirable. Cities will become much cleaner places, which is to everyone's benefit.
However, there are some fascinating cases that work: https://www.stuytown.com/sustainability/solar This project is almost complete and seems to be working really well.